But as Al-Jazeera television broadcast images of Private First Class Keith Matthew Maupin surrounded by masked and armed insurgents, two Japanese hostages were released in Baghdad after three days in captivity.

Sheikh Abdul Salam Kubaissi, a senior member of the Committee of Muslim Scholars, told AFP the two were in "very good health" and had been handed over to the Japanese embassy. Three other Japanese hostages were freed Thursday.

Maupin was shown by the Qatar-based Al-Jazeera sitting on the floor in US military fatigues and a standard-issue floppy hat. He seemed scared and avoided looking at the camera.

The masked gunmen standing around him have demanded the release of insurgents being held by US-led forces in Iraq.

Maupin was among nine Americans, including another soldier and seven contractors, who went missing after an attack on a convoy near Baghdad airport on April 9 that left one US soldier dead and 12 wounded.

There has been no news of the other missing soldier, Sergeant Elmer C. Krause, 40, but at least one of the civilian contractors -- truck driver Thomas Hamill, 43 -- is also believed to be a hostage somewhere in Iraq.

The US-led coalition estimates around 40 foreigners from 12 countries have been abducted as part of a kidnapping campaign designed to break the resolve of coalition partners in Iraq.