A failed American attempt to abduct two senior Iranian security officers on an official visit to northern Iraq was the starting pistol for a crisis that 10 weeks later led to Iranians seizing 15 British sailors and Marines.

The two senior Iranian officers the US sought to capture were Mohammed Jafari, the powerful deputy head of the Iranian National Security Council, and General Minojahar Frouzanda, the chief of intelligence of the Iranian Revolutionary Guard, according to Kurdish officials.

The two men were in Kurdistan on an official visit during which they met the Iraqi President, Jalal Talabani, and later saw Massoud Barzani, the President of the Kurdistan Regional Government (KRG), at his mountain headquarters overlooking Arbil.

"They were after Jafari," Fuad Hussein, the chief of staff of Massoud Barzani, told The Independent. He confirmed that the Iranian office had been established in Arbil for a long time and was often visited by Kurds obtaining documents to visit Iran. "The Americans thought he [Jafari] was there," said Mr Hussein.