海角大神

A bomb ripped a bus apart in Volgograd听on Monday, killing 14 people in the second deadly attack blamed on suicide bombers in the southern Russian city in 24 hours and raising fears of Islamist attacks on the Winter Olympics.

笔谤别蝉颈诲别苍迟听Vladimir Putin, who has staked his prestige on February's Sochi Games and dismissed threats from Chechen and other Islamist militants in the nearby听North Caucasus, ordered tighter security nationwide after the morning rush-hour blast.

The previous day's similar attack killed at least 17 in the main rail station of a city that serves as a gateway to the southern wedge of Russian territory bounded by the Black and Caspian Seas and the Caucasus mountains.

On Monday, the blue and white trolleybus - powered by overhead electric cables - was reduced to a twisted, gutted carcass. Bodies were strewn across the street as Russians prepared to celebrate New Year, the biggest annual holiday.

Windows in nearby apartments were blown out by the blast, which听Russia's听foreign ministry听condemned as part of a global terrorist campaign.

"For the second day, we are dying. It's a nightmare," a woman near the scene told Reuters, her voice trembling as she choked back tears. "What are we supposed to do, just walk now?"

"Identical" shrapnel to that in the rail station indicated that the two bombs were linked, investigators said.

"There was smoke and people were lying in the street," said听Olga, who works nearby. "The driver was thrown a long way. She was alive and moaning ... Her hands and clothes were bloody."

There was no immediate claim of responsibility for either of the two attacks. Investigators said they believed a male suicide bomber was responsible for Monday's blast. In Sunday's attack, the federal听Investigative Committee听initially described the bomber as a woman from听Dagestan, a hub of Islamist militancy on the Caspian, but later said the attacker may have been a man.

Citing unnamed sources, the Interfax news agency said the suspected attacker in Sunday's blast was an ethnic Russian convert to Islam who had moved to听Dagestan听and joined militants there early in 2012.

Volgograd was also the scene of an attack in October, when a woman from听Dagestan听killed seven people in a suicide bus blast.

Security

The violence raises fears of a concerted campaign before the Olympics, which start on Feb. 7 around Sochi, a resort on the听Black Sea听at the western end of the Caucasus range, 700 km (450 miles) southwest of Volgograd.

In an online video posted in July, the Chechen leader of insurgents who want to carve an Islamic state out of the swathe of mainly Muslim provinces south of Volgograd, urged militants to use "maximum force" to prevent the Games from going ahead.

"Terrorists in Volgograd听aim to terrorise others around the world, making them stay away from the Sochi Olympics," said听Dmitry Trenin, an analyst with the听Moscow听Carnegie Centre.

North Caucasus听militants have also staged attacks in听Moscow听and other cities, the most recent in the capital being an airport suicide bombing three years ago that killed 37 people.

International Olympic Committee听笔谤别蝉颈诲别苍迟听Thomas Bach听condemned the "despicable attack on innocent people" and said he had written to Putin to express condolences and confidence that听Russia听would deliver "safe and secure games in Sochi".

It was unclear why Volgograd听has been hit, though it is close to the restive regions. It also has resonance in Russian national identity as the scene of the battle that turned the course of World War Two, when the city was known as Stalingrad.

Putin visited in February to mark the battle's 70th anniversary. City leaders have revived the old name for special occasions as Stalin's image has been somewhat rehabilitated under Putin, while Stalin remains a hate figure to Chechens, whose nation was deported en masse on his orders.

Putin has staked his personal reputation on a safe and successful Olympics. This month, he freed jailed opponents including oil tycoon听Mikhail Khodorkovsky听and the Pussy Riot punk band to remove causes for criticism at the event.

Intended to showcase how听Russia听has changed since the collapse of Soviet communism in 1991, the Games have also been a focus for complaints in the West and among Russian liberals that Putin has stifled dissent and encouraged intolerance.

Putin was first elected in 2000 after winning popularity for a war on Chechen rebels who had bid for independence after the break up of the听Soviet Union. Attacks by Islamist militants whose insurgency is rooted in that war have clouded his 14 years in power and now present his biggest security challenge.

In a statement, the听Foreign Ministry听called on world powers to stand together against "terrorists" and named Doku Umarov, the Chechen warlord who leads the insurgency in the听North Caucasus, as among those fomenting violence.

"We will continue our consistent fight against an insidious enemy that can only be stopped together," the ministry said.

Likening the Volgograd听bombings to attacks in the听United States,听Syria,听Afghanistan听and elsewhere, it criticised those who seek to justify some such violence - an apparent dig at Western powers who have supported听Syria's insurgents and who, at least in the 1990s, showed some sympathy for Chechen rebels.

"The听United States听stands in solidarity with the Russian people against terrorism,"听White House National Security Council听spokeswoman听Caitlin Hayden听said. "The听U.S. government听has offered our full support to the听Russian government听in security preparations for the Sochi Olympic Games, and we would welcome the opportunity for closer cooperation for the safety of the athletes, spectators, and other participants."

Russia听has in the past complained that Western countries do not consider its听North Caucasus听militants a threat, although听Moscow听cooperated with Washington after the听Boston听Marathon bombings that killed three people in April. The听Boston听suspects, two brothers, were Chechens who had lived in听Dagestan.

On Twitter, British Prime Minister听David Cameron听said he was "shocked & saddened" by the attacks. "I've written to President Putin to say the UK will help听Russia听in whatever way we can."

罢别苍蝉颈辞苍蝉听

Police said additional officers were deployed to railway stations and airports nationwide. In Volgograd听province, more than 4,000 police and interior troops were activated in operation Anti-terror听Whirlwind, checking documents and searching for suspicious people, Interfax quoted regional police as saying.听Itar-Tass听said they were focusing on migrant workers.

"There is a horrible feeling of helplessness against these monsters," said librarian听Margarita Savicheva, 50. "I fear for my daughter, who also takes the trolleybus. Something diabolical has come to our town."

The police force in Volgograd, a city of a million people, has been depleted as some 600 officers were redeployed to Sochi to help with Olympics security a police officer told Reuters.

More attacks can be expected before the Olympics and nearby cities are easier targets than Sochi itself, said听Alexei Filatov, a prominent former member of听Russia's elite anti-terrorism force, Alfa.

"The threat is greatest now because it is when terrorists can make the biggest impression," he said. "The security measures were beefed up long ago around Sochi, so terrorists will strike instead in these nearby cities like Volgograd."

The attacks also threaten to fuel ethnic tension, which has increased with an influx of migrants from the poor Caucasus and Muslim Central Asian nations to Russian cities in recent years.

"They need to be chased out of here. It has become a transit junction - there are all these non-Russians, both good and bad," said听Olga, a saleswoman at a store near the mangled bus.

Several dozen nationalists held a protest outside a chapel in the city on Monday and police detained more than 20 of them.

"We are Russian; we must not be afraid," said听Mikhail Yasin, a protester who lit a candle for bombing victims. "God is with us. We are in our own land and no terrorist can frighten us - nor can the police."

(Additional reporting by Alissa de Carbonnel; Writing by Steve Gutterman; Editing by John Stonestreet, Alastair Macdonald and Peter Graff)