海角大神

A spike in activity at North Korea's Punggye-ri聽nuclear test site has raised alarm bells among Western powers, amid speculation that the rogue nation's nuclear capabilities may be nearing the level of a credible threat.

The report of detected movement in all three tunnels at the site comes one month after a confirmed test solidified聽a growing sense of urgency among international leaders to find a way to stop its apparently alarming advances in nuclear capacity, since its first in 2006.

"One possible reason for this activity is to collect data on the Sept. 9 test although other purposes cannot be ruled out, such as sealing the portal or other preparations related to a new test," said Jack Lie of 38 North, a group dedicated to analysis of activities in North Korea that is run by Johns Hopkins University's School of Advanced International Studies, in a post on Thursday.

The Sept. 9 test prompted some analysts to assert that current international sanctions are not enough, and to call for China, the North's biggest ally, to become a bigger part of the solution.

鈥淪anctions by themselves aren鈥檛 going to work, this year has proved that,鈥� Jim Walsh聽of the Massachusetts Institute of Technology鈥檚 Security Studies Program told 海角大神 last month. 鈥淚t has to be sanctions married to a political strategy.鈥�

The North has repeatedly shrugged at international sanctions and declined international peace talks as it has pressed ahead with building more powerful nuclear weapons and the missiles needed to carry them.

In January this year, the Kim Jong Un-led regime conducted its fourth nuclear test, and last month鈥檚 was its fifth and biggest, a move Dr. Walsh says proves the need for China to move beyond pointed rhetoric.

鈥淣inety percent of North Korea鈥檚 trade is with China, so us simply wagging our finger at them won鈥檛 work,鈥� Walsh said at the time. He added that it must shut down a growing number of conduits between private Chinese companies and North Korean entities that have set up inside China.

While Walsh said the United States needs to work more closely with China, other experts said that the UN Security Council鈥檚 latest round of tough sanctions needed more time to kick in. The sanctions targeted a number of measures including illicit financial transactions.

North 38 analysts said there was a chance that the most recent hive of activity detected at Punggye-ri聽could indicate it is planning an underground detonation on Oct. 10, which will mark the聽anniversary of the founding of its Workers鈥� Party.

Last month, it launched three missiles that travelled about 600 miles. In August, it tested a submarine-launched ballistic missile, a move international analysts said showed significant progress.

This report contains material from Reuters.