Iraqi kidnappers have threatened to kill a US hostage unless US forces lift their siege on Falluja, Qatar-based Al-Jazeera TV channel reported Saturday.

"Our only demand is to lift the siege of the city of the mosques(Falluja) within 12 hours as from 6:00 pm (1500 GMT) on Saturday," said a voice on a tape aired by the TV channel.

"Otherwise, he will be treated worse than those who were killed and burned in Falluja," threatened the voice, referring to four American contractors killed in the city last week.

Al-Jazeera showed footage of the US hostage identified as Thomas Hamill, the same man who had earlier appeared on Britain's Sky News, saying he had been seized after a convoy was attacked.

According to the TV channel, the tape was received from a group called itself as "the mujahedeen of Iraq to US forces." 

Source: Xinhua