A high-ranking officer from North Korea's military intelligence agency fled to South Korea last year, the Seoul government confirmed Monday.

The colonel, whose name was withheld by the South Korean government, worked for the North Korean military's General Reconnaissance Bureau. The agency is believed to be behind two deadly attacks blamed on Pyongyang that killed 50 South Koreans in 2010.

The General Reconnassance Bureau also deals in cyberwarfare, and it is widely suspected of being behind the 2014 hack attack on Sony Pictures Entertainment.

South Korea's Yonhap News Agency reported that the colonel is viewed as an elite member of North Korean society by other defectors from the Communist dictatorship.

"He is believed to have stated details about the bureau's operations against South Korea to authorities here," the agency quoted a source as saying.

The announcement of the colonel's defection came three days after South Korea revealed 13 North Koreans working at the same restaurant in a foreign country had defected to the South, the largest group defection since North Korea's young leader Kim Jong Un took power in late 2011. South Korean media reported the restaurant is located in the eastern Chinese city of Ningbo. (snip)

Yonhap also reported that a number of low-level North Korean officials based in foreign countries have sought asylum to avoid being caught in one of Kim Jong Un's purges. South Korea's Unification Ministry confirmed Monday that a North Korean diplomat based in Africa also separately defected to South Korea last year. It didn't elaborate.