NATO says alliance and Afghan soldiers have killed 52 insurgents in a clash in southern Afghanistan, while a roadside bomb in eastern part of the country killed three top police officials.

The alliance says the insurgents were killed in Charchino district of Uruzgan province late Sunday. There were no reports of NATO casualties.

Afghan police say the three police officials - the provincial police chief, intelligence chief and administrative chief - were killed Monday in the Khogyani district of Nangarhar province. They were on the way to investigate burning of a school.

Meanwhile, the British commander of NATO troops in Afghanistan, General David Richards, arrived in Pakistan to discuss the Taleban insurgency with military officials.

His visit comes amid concern about Taleban militants moving across the rugged border with Pakistan.

General Richards took over command of foreign troops across Afghanistan last week.

Britain's Sunday Times newspaper reported that General Richards has satellite pictures and videos of Pakistan's military intelligence service training Taleban fighters.

But NATO officials in Afghanistan have rejected the newspaper report, saying Richards will have a full and frank discussion aimed at developing military cooperation with Pakistan.

Afghan officials have repeatedly said that Taleban remnants hiding in Pakistan stage attacks inside Afghanistan.

Pakistan rejects such claims, saying it has deployed some 80,000 troops on its border with Afghanistan to track down militants. But Pakistani officials also acknowledge that it is virtually impossible to secure the entire border, which is rugged and porous.

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