An Iraqi militant group is claiming that it shot down a British military transport plane which crashed north of Baghdad, killing about 10 troops.
The Ansar al-Islam group said in a statement posted Sunday on an Islamic Web site that its fighters tracked the aircraft, "which was flying at a low altitude, and fired an anti-tank missile at it."
The plane crashed Sunday while flying from Baghdad to the town of Balad.
"Thanks be to God, the plane was downed and a huge fire and black clouds of smoke were seen rising from the location of the crash," said the statement.
British and U.S. military officials have not said what they think caused the crash, which occurred about a half hour after polls closed in Iraq's elections.
Asked about the Ansar claim, a spokesman for Britain's Ministry of Defense said: "We can't confirm any of that."
British officials at the crash site are investigating.
The wreckage of the Hercules is scattered over a large area, suggesting a mid-air explosion, according to a senior U.S. military officer in Iraq. The plane went down 25 miles northwest of Baghdad.
Established after the Sept. 11, 2001, attacks, Ansar al-Islam is one of Iraq's older extremist groups and it has been linked to al-Qaida.
British Foreign Secretary Jack Straw said the death toll was "the largest single loss of British service lives" since U.S. and British troops invaded Iraq in March 2003. Previously the largest number was six.
British Prime Minister Tony Blair paid tribute to the casualties in a televised speech praising Iraq's election.
"Our thoughts and prayers are with the families of those who lost their lives today. They can be so proud of what their loved ones accomplished. This country and the wider world will never forget them," Blair said Sunday.
British military officials have said "around 10" troops were killed.
Britain has some 9,000 troops in Iraq, mostly in the south of the country near the city of Basra.