BAGHDAD (AFP) -- Six American and four British troops were killed in attacks across Iraq, coalition forces announced on Thursday, as a U.S. helicopter crashed south of Baghdad and insurgents ambushed Iraqi soldiers.

The bloody 24 hours for foreign troops and the local army the Americans and British are trying to train, came with preparations underway for Iraqi security troops to take control of the fourth province in the Shiite south.

The British soldiers and a civilian interpreter in the same vehicle were killed outside the southern city of Basra in a complex attack involving a roadside bomb, small-arms fire and rocket-propelled grenades.

Two of four Britons were women from the Queen Alexandra's Royal Army Nursing Corps and the Intelligence Corps, the ministry of defense said in London.

Their deaths bring to four the number of British female personnel killed since the start of the U.S.-led invasion in March 2003.

Another soldier was seriously wounded in what was the deadliest attack against British forces based in Iraq since November, when four servicemen were killed in a bomb attack on their boat patrol in the Shatt al-Arab waterway.

"It is with deep regret that we can confirm that four British soldiers and a civilian interpreter were killed in a roadside bomb attack against a Warrior patrol west of Basra this morning," said the British ministry of defence.

British Lieutenant Colonel Kevin Stratford-Wright said the patrol repelled an initial attack from gunmen, hitting at least one assailant with return fire, before moving out of the urban area and coming under attack.

West of Basra, the unit was hit by a roadside bomb, followed up with small-arms fire and rocket-propelled grenades, he told AFP by telephone from the British headquarters in southern Iraq.

"During that (roadside bomb) attack the five people were killed, all of whom were in the same vehicle. A further soldier who was in the vehicle is very seriously wounded," he said.