KABUL, Afghanistan (CNN) -- An explosion struck a vehicle carrying British troops Sunday, killing two and wounding two others in southern Afghanistan, Britain's Defence Ministry said Monday.
The incident occurred in Kandahar province and involved troops from Britain's Royal Air Force.
"The men were conducting a routine patrol two kilometers west of Kandahar Airfield when the vehicle they were traveling in hit an explosive device," the ministry said.
The troops are deployed with NATO's International Security Assistance Force.
Also Sunday, Taliban militants attacked a police post in southern Afghanistan and killed 11 officers as they lay sleeping, an official told CNN.
It was the second time in two days that police officers have been killed in militant attacks in the province of Kandahar.
The Kandahar police official said an initial investigation revealed that an officer may have "had a hand" in the attack because the militants were able to fatally shoot the officers while they were asleep.
The attack occurred in the Arghandab district, some six miles (10 km) north of Kandahar city.
On Saturday, four officers were killed when militants attacked a police unit as they were eradicating poppy fields, officials said.
In recent months, militants have stepped up attacks against local police, coalition troops and NATO-led forces.
Journalist Farhad Peikar in Kabul contributed to this report.