'Torture houses' found in Falluja

One site resembles that where UK hostage Ken Bigley was held

US forces say they have found about 20 houses in Falluja where hostages may have been held and tortured.

American reporters were shown two houses from which soldiers said they had removed handcuffs, shackles, blood-caked knives and bayonets.

The British hostage Ken Bigley may have been held in one of the houses but investigators caution the sites have not yet undergone forensic testing.

In new violence, a senior Muslim cleric was assassinated in the city of Mosul.

'Chicken wire'

Late on Sunday, two reporters from CNN and the New York Times were shown two houses thought to have been used to hold foreign hostages.

One house contained a chicken-wire cage similar to that in which Ken Bigley appeared in a videotape shortly before he was beheaded.

In the other was a black banner bearing a yellow sun and the words Tawhid and Jihad (Unity and Holy War), the former name of the group said to be led by Jordanian militant Abu Musab al-Zarqawi.

The group is thought to be responsible for many bombings and beheadings across Iraq and it claimed the kidnapping and killing of Mr Bigley and two American colleagues, Jack Hensley and Eugene Armstrong.

The group's banner has been a regular feature on videotapes of hostages.

The reporters were shown a catalogue of photographs of items removed from the two houses for testing - including apparently blood-crusted knives similar to those used to behead hostages.

The two houses are among about 20 such "atrocity sites", US intelligence officer Maj Jim West told reporters

"Murder and torture" took place at these sites, Maj West said, showing reporters images of bloodstained walls and floors.

Pending DNA and other forensic tests and detailed comparisons of the houses and videotape settings, officials caution that there is no proof that hostages were held there.

US-led troops trying to pacify Falluja continue to encounter sporadic resistance. They say 1,450 suspected resistance fighters have been rounded up.

Cleric shot

Sheikh Feydhi Mohammed al-Feydhi, a relative of a senior member of the Association of Muslim Scholars, was shot dead in Mosul.

The Association told Reuters news agency he had been shot in a drive-by shooting but a health official told the Associated Press he had been shot by masked men when he opened the door of his home to them.

The motive for his killing is unclear. The Association has called for a boycott of the elections scheduled in Iraq for 30 January.

Four election officials earlier fled Mosul after receiving death threats and shop owners have been warned not to distribute voter registration forms.

Reports also suggest at least three more bodies of Iraqi men have also been found in Mosul.

That brings to 15 the number of Iraqi men, mainly soldiers, thought to have been killed since Saturday.