A North Korean Army officer has testified that the North Korean military attacked the South Korean Navy corvette Cheonan before it sank in the West Sea on March 26, the head of a South Korean activist group claimed Monday. Choi Sung-yong of the Family Assembly Abducted to North Korea said, "It seems that the Cheonan was sunk in a premeditated North Korean operation."

Choi published a transcript of a telephone conversation with what he says is a senior North Korean Army officer.

According to the transcript, the officer says, "Thirteen commandos who left from Cape Bipagot sank the Cheonan. Many people as well as military officers already know who attacked the ship."

The officer claims the motive was revenge. "After the North lost the sea skirmish in November last year, Kim Jong-il gave an order to take revenge. He gave the order when he visited the naval fleet command in Nampo."

The officer according to the transcript claims Gens. Kim Yong-chol and U Dong-chuk traveled between Pyongyang and Nampo frequently to visit the fleet command to work out an operational plan. "Navy Commander Jong Myong-do stayed in Nampo until the mission was accomplished," he added.

Kim Yong-chol, the director of the General Reconnaissance Bureau in charge of espionage operations against the South, has been consistently fingered by South Korean intelligence agents as the man behind the attack.

U Dong-chuk, the senior deputy chief of the State Security Department and a member of the National Defense Commission, and Navy Commander Jong Myong-do were promoted to full generals on Kim Il-sung's 98th birthday last Thursday. They were two of the four lieutenant generals who were promoted the same day.

Their promotions stoked suspicions here since U was promoted to a full general only a year after he was promoted to lieutenant general. Jong was promoted unexpectedly after his position became uncertain following North Korea's ignoble defeat in the sea skirmish last year.

"Some of the 13 commandos who left Cape Bipagot before they sank the Cheonan are acquaintances of mine," the alleged officer claims according to the transcript. "It seems it was such an important mission that a semi-submersible which was made originally for a crew of three was remodeled for the mission."

He claims the Cheonan's sinking lifted soldiers' morale and the 13 commandos "are being treated as heroes."

"They apparently spent a lot of time practicing camouflage by sneaking around fleet of North Korean and Chinese fishing boats operating near Baeknyeong Island," the officer says. "It seems lik ely that a bigger event will occur in the future given that they are operating also in the East Sea, camouflaging themselves there."

Commenting on North Korean broadcasts' denial of the North's involvement, the transcript has him saying, "It's natural for them to deny involvement, isn't it? We're tired since we've always been on emergency alert."