Pakistan's Prime Minister, Nawaz Sharif, says Pakistan has asked the Taleban authorities to close down training camps in Afghanistan.

Nearly 40 people have been killed in sectarian violence in Pakistan in the past 10 days, mainly members of the minority Shiite community.

On Thursday, a senior official from Pakistan's state-run television PTV was shot dead by two attackers on a motorcycle in Rawalpindi.

Aun Mohammad Rizvi, PTV controller of programmes, was a Shiite Muslim.

Late on Wednesday, three doctors - two Shiites and a Sunni Muslim - were killed in the southern port city of Karachi.

Mohammad Nisar, a Sunni Muslim and an influential member of Pakistan's main Islamic party, Jamaat-i-Islami, was gunned down in his car by unidentified assailants when he stopped at traffic lights.

Arrests

Asked about the current wave of sectarian violence in Pakistan, the prime minister said that the Pakistani authorities had made a number of arrests in recent days.

Police have increased security checks in Pakistani cities

Interrogations of those arrested, he said, had established that they had received training at camps in Afghanistan and he said that a few days ago the director general of Pakistan's main intelligence organisation, the Inter Services Intelligence, went to Kandahar and met the Taleban leader Mullah Mohammad Omar.

He said that the Pakistani delegation said that the camps must be closed immediately and that the training must be stopped.

When asked whether the Taleban were directly responsible for the training, the Pakistani Prime Minister would not be drawn.

"I don't want to get into that until we've received a response from the Taleban," Mr Sharif said.

The Taleban have already denied any involvement in the training.

Almost 40 people have been killed in the past 10 days

Asked what he would do if the Taleban did not co-operate, he said Pakistan would then have to consider its next step.

A Taleban spokesman has said that the Taleban will co-operate with Pakistan and that it will closely watch the activities of suspected Pakistanis in Afghanistan.