BAGHDAD, Sept. 14 (Xinhua) -- U.S. troops have arrested a senior member of al-Qaida in Iraq, U.S. top spokesman said on Thursday.

    In an operation on Tuesday, U.S. troops netted a personal associate of al-Qaida in Iraq's new leader Abu Ayyob al-Masri, who took over the organization after the killing of Abu Musab al-Zarqawi by the U.S. army on June 7, said Maj. Gen. William B.Caldwell.

    The man, who was not identified, was the leader of assassination, kidnapping and bomb making cells in Baghdad, he said.

    He added that the detainee "also played a key operational role in terrorist activities prior to and during the operation in Fallujah in Nov. 2004."

    Meanwhile, a senior Iraqi Interior Ministry officer said that another al-Qaida leader in Iraq has been killed in an operation by Iraqi security forces.

    Abu Jaafar al-Lybi was killed and two of his assistants were arrested on Sunday, according to Brigadier General Abdel Karim Khalaf.

    Al-Lybi was heading criminal operations in Baghdad and Diyala province in north east of Baghdad, he said. During the operation, the letters written by al-Lybi to Osamabin Laden and to Masri to explain his work and achievements in Iraq were found, he added. Enditem