Riyadh: An al-Qaida group said it killed American hostage Paul M Johnson Jr, posting an Internet message that showed three photographs of a severed head that appeared to be his.

The message, in the name of the Fallujah Brigade of al-Qaida in the Arabian Peninsula, appeared as a 72-hour deadline set by the group ended.

Saudi security officials later said Johnson's body was found in the rural al-Munisiyah district, 40 kms northeast of Riyadh.

The officials, speaking on condition of anonymity, said police had cordoned off the area, blocking all roads leading to the area of farms and villas used by wealthy residents as resorts.

It was not clear whether police had surrounded any suspects.

Security officials said there was a tight police cordon around the Jerusalem neighborhood, in the heart of Riyadh, where there were clashes ongoing. The neighborhood is some 30 kms south of the al-Munisiyah area.

The pan-Arab satellite station Al-Arabiya reported that three militants were killed in clashes with Saudi security in Riyadh's al-Malz neighborhood shortly after the discovery of Johnson's body. It said helicopters were taking part in the chase in downtown Riyadh.

Johnson was kidnapped June 12 by militants who threatened to kill him by Friday (June 18, 2004) if the kingdom did not release its al-Qaida prisoners.