A group of armed, masked men have issued a public warning to Jordanian militant Abu Musab al-Zarqawi to leave Iraq on pain of death.
The US believes Zarqawi beheaded an American hostage
A previously unknown group, calling itself the Salvation Movement, accused him of murdering innocent Iraqis and defiling the Muslim religion.
The men said unless he left immediately he would be hunted down and killed.
Mr Zarqawi and his followers have been blamed for a string of attacks in Iraq and the beheading of foreign hostages.
"We have started preparing... to capture him and his allies or kill them and present them as gift to our people," one of the men said in the video, broadcast on the Dubai-based al-Arabiya TV network.
"We will do to you what the coalition forces have failed to do."
The warning extended to the friends, followers and protectors of Mr Zarqawi.
"This is the last ultimatum to those who give him shelter. This is the last warning," the masked man says.
The statement accused the fugitive of "heinous acts which killed innocents" in attacks across Iraq.
"What religion is he clinging to? Islam is a religion of forgiveness," it said, condemning the murder of foreign workers and threats against interim Prime Minister Iyad Allawi.
Arrest in Jordan
Meanwhile Jordanian police were reported to have detained Mr Zarqawi's brother-in-law.
The Arab TV channel al-Jazeera said Saleh al-Hami, who is married to Mr Zarqawi's sister, was arrested after appearing on one of its shows.
A Jordanian government official said he was not being held on suspicion of terrorism, according to the AP news agency.
Mr Zarqawi, a 38-year-old Jordanian, is believed to have strong links to al-Qaeda and is accused by the US of being behind a spectacular string of suicide bombings in Iraq.
Mr Zarqawi's group has also claimed responsibility for the beheadings of an American and a South Korean hostage.