A British military helicopter that crashed in the Iraqi city of Basra on Saturday was hit by a missile, a military spokeswoman in Basra said.
British forces sealed off the area around the incident, witnesses told Reuters.
"We can confirm that there has been a helicopter crash in Basra," said a British military spokesman in the city.
"British troops are on the scene assisting and emergency services are present," he added.
Video footage from Iraqi television showed orange flames and large plumes of black smoke curling into the sky.
British troops were seen running through the streets, firing shots into the air.
The helicopter crashed into a building near the provincial governor's office, but there were no casualties on the ground, police said.
Basra, Iraq's second largest city, is 550 kilometres south of Baghdad. It is policed mainly by British troops, of whom some 8,000 are still in Iraq along with 133,000 Americans.