Afghan officials say police mistook U.S.-led coalition troops on a night patrol for Taleban forces and fired on them, sparking a battle that left seven Afghan police dead and at least four wounded.

Afghan authorities said the soldiers, who had been on an anti-Taleban operation, called in an air strike after coming under fire in the eastern province of Nangarhar around midnight.

Presidential spokesman Karim Rahimi called the incident heartbreaking and said it was the result of a misunderstanding and lack of communication.

Earlier, the U.S. troops had been accused of attacking the police outpost.

In southern Afghanistan, U.S. military authorities said Coalition and Afghan troops killed more than 24 suspected Taleban fighters during an eight-hour battle Monday in Kandahar province.

Also on Monday, Afghan police said they arrested 11 suspects in connection with an assassination attempt Sunday on Afghan President Hamid Karzai.

The arrests came as the United Nations condemned Sunday's attack in the eastern province of Ghazni, calling it "an outrage."

On Sunday, suspected Taleban insurgents fired several rockets at a school where Mr. Karzai was giving a speech, narrowly missing their target.

Some information for this report was provided by AFP and AP.