Militants threaten to kill U.S. Marine

BAGHDAD (Reuters) - An Iraqi militant group has issued footage of a man it says is a captured U.S. Marine and threatened to behead him, further heightening tension ahead of the June 30 formal handover of sovereignty.
Video shown on Qatar-based Arabic channel Al Jazeera on Sunday showed a blindfolded man in a camouflage uniform, and an apparent Marine Corps identity card that named him as Wassef Ali Hassoun.
Jazeera said the group threatened to behead Hassoun unless Iraqi prisoners are freed.
The U.S. military said it was investigating the claim.
Militants in Iraq have already seized three Turks and a Pakistani man over the past week in a new spate of kidnappings just days before the formal handover of sovereignty by occupying forces to an interim Iraqi government on June 30.
Fighters loyal to al Qaeda ally Abu Musab al-Zarqawi said on Saturday they were holding the Turks and would behead them within 72 hours unless Turks stopped working with U.S. forces.
The threat has cast a shadow over U.S. President George W. Bush's visit to Turkey for a NATO summit on Monday and Tuesday.
In a separate video tape aired on Al Arabiya television on Sunday, unidentified gunmen said they had seized a Pakistani hostage near Balad, north of Baghdad, and would kill him within three days unless Iraqi prisoners were released from jail.
The footage showed the man, who had an identity card given to contractors working for U.S. forces, urging Pakistan's president to shut down the country's embassy in Iraq.
Turkey and Pakistan are not part of the U.S.-led occupation force in Iraq but many nationals work as drivers, cooks, cleaners and support staff for U.S. troops.