A suicide bomber blew himself up inside a courtroom in southwestern Pakistan, killing at least 15 people and injuring 25 others. From Islamabad, Ayaz Gul reports.

Pakistani security officials examine the site of a suicide bombing at the District Courts in Quetta, 17 Feb 2007

The attack took place in Quetta, the capital city of the southwestern Baluchistan province bordering Afghanistan. Police and witnesses say the suicide attacker detonated the powerful bomb while the court was in session. A senior civil judge and several lawyers are among those killed in the bombing.

Provincial police Chief Tariq Khosa says an investigation is underway to determine the motives. He says that stopping suicide bombings is always difficult, dismissing criticism that poor security measures led to the attack inside the high-security courthouse.

"We will carry out investigations from all possible angles," he said, adding that "the best of the places, the more secure places are also made inroads by suicide bombers." Khosa said "We had taken all possible precautions but this is an unfortunate incident in which we have to face the situation."

The southwestern Pakistani region, where Saturday's suicide bombing occurred, is widely believed to be used by Taleban leaders for planning attacks against Afghan and foreign forces in Afghanistan.

Frequent attacks against official installations have occurred in the Pakistani province in recent years that authorities blame on ethnic Baluch militants fighting for greater autonomy.

Security officials are unsure whether the Taleban or the ethnic Baluch were behind Saturday's bombing.

Under mounting pressure from the United States and Afghanistan, Pakistan has intensified efforts to eliminate militant sanctuaries on its territory.

In recent months, authorities in Baluchistan have detained hundreds of suspected Taleban militants and handed them over to the Afghan government. The Pakistani government also has decided to shut down two camps for Afghan refugees in the province, saying Taleban are using the facilities for their terror activities.

Pakistan is a key ally of the United States in its war on terror and has witnessed scores of deadly terrorist attacks that authorities have linked to the al-Qaida terror network and the Taleban.