At least seven children and several militants have been killed in a U.S.-led coalition air strike. According to the coalition, the air strikes targeted a suspected al-Qaeda militant compound, which also contained a mosque and a school.

The operation took place late on Sunday in the Southeastern Paktika province close to the border with Pakistan.

Earlier, at least 35 people, most of them policemen, were killed in a suicide bomb attack on a bus in Kabul. At least thirty others were wounded.

The Taliban claimed responsibility for the blast, which was the bloodiest attack since the U.S.-led invasion began in 2001.

The Interior Ministry says five foreigners were among the injured.

The Police Academy bus was filled with instructors.

“The officers were getting on the bus when the suicide bomber attacked. The investigation is still ongoing to know how it happened,” Zarah Ahmad Moqbil, Afghan Interior Minister, said.

A civilian vehicle close to the bus was also damaged, and several foreigners inside were wounded adding to the scene of carnage.

The European Union on Sunday took over responsibility for police training in the capital, Kabul. The EU envoy to Afghanistan, Francesc Vendrell, was quick to condemn the attack.

“Today, we have witnessed another cowardly attack against the police forces of this country. And I think the fact that the police forces are the target and – not only today but in the past – attests to the importance of the police,” Mr Vendrell stressed.  

Afghan government officials, police and army soldiers are commonly targeted by Taliban militants trying to bring down the U.S-backed government.

Estimates indicate that more than three hundred Afghan police, army and intelligence personnel have been killed so far this year.