Israeli commandos seized nuclear material of North Korean origin during a daring raid on a secret military site in Syria before Israel bombed it this month, according to informed sources in Washington and Jerusalem.
The attack was launched with American approval on September 6 after Washington was shown evidence the material was nuclear related, the well-placed sources say.
They confirmed that samples taken from Syria for testing had been identified as North Korean. This raised fears that Syria might have joined North Korea and Iran in seeking to acquire nuclear weapons.
Israeli special forces had been gathering intelligence for several months in Syria, according to Israeli sources. They located the nuclear material at a compound near Dayr az-Zwar in the north.
Evidence that North Korean personnel were at the site is said to have been shared with President George W Bush over the summer. A senior American source said the administration sought proof of nuclear-related activities before giving the attack its blessing.
Diplomats in North Korea and China believe a number of North Koreans were killed in the strike, based on reports reaching Asian governments about conversations between Chinese and North Korean officials.
Syrian officials flew to Pyongyang, the North Korean capital, last week, reinforcing the view that the two nations were coordinating their response.