KABUL: Two Afghan police officers were killed in a clash with foreign troops conducting a night raid southwest of the Afghan capital, Kabul, early on Saturday, a provincial police chief said, adding to Afghan pressure to stop the raids.

Night raids, which foreign troops say are one of their most effective weapons in the fight against insurgents, are a major cause of friction between President Hamid Karzai and his Western backers. Karzai has said repeatedly he wants them stopped.

Saturday's incident happened when the soldiers, who were involved in a night raid which had not been coordinated with the police, ignored orders to halt when spotted by officers in Ghazni province, said Ghazni police chief Zorawar Zahid.

Shots were fired in the resulting clash, he said.

“Foreign troops were planning to conduct night raids but a firefight took place when they failed (to obey) police orders to stop,” Zahid said.

A spokesman for the Nato-led International Security Assistance Force said the coalition was aware that an incident had taken place and was investigating. It declined to give further details.

Afghanistan wants the United States and Nato to agree to stop carrying out night raids on Afghan homes as a precondition to signing a long-term alliance with Washington, Karzai said on Wednesday.

Parts of Ghazni province are expected to be included in the next phase of a security handover to Afghan forces under a plan agreed by the coalition and for foreign combat troops to leave Afghanistan by the end of 2014.