At least 40 killed in attack at Pakistan shrine

ISLAMABAD, Pakistan - Pakistan's Taliban militants were at the center of fresh investigations Sunday linked to new suicide attacks being planned against prominent targets, after two suicide bombers caused devastating carnage at a shrine in eastern Pakistan, killing at least 40 people, a senior intelligence officer and a police officer told CBS News.

The attack at the shrine in the city of Dera Ghazi Khan in the south of Pakistan's Punjab province came on a day when followers of a "sufi" saint had gathered during an annual meeting to pay their respects. The attack immediately prompted security officials to warn of further attacks likely to take place in the coming days.

"We had followed various indications including messages intercepted recently which spoke of a big campaign about to come together," said the senior intelligence officer who spoke to CBS News on condition of anonymity.

A police officer based in the provincial capital of Lahore (who also spoke to CBS News on condition of anonymity) said, "The most disturbing aspect of this attack is that it tells us once again that the Taliban and their al Qaeda patrons are alive and able to stage such major attacks."

The police officer said that arrests of several Islamist militants in recent months had also indicated that the Taliban were looking to target the Punjab province, widely known as Pakistan's heartland and home to more than 60 percent of the country's population.

"The Taliban are obviously keen to destabilize Pakistan, and attacks in the Punjab are of major value" in doing so, added the police officer.

The shrine which was struck is one of the many across Pakistan known to be a symbol of values spread by "sufi" saints across south Asia. Their teachings, which promoted conciliatory attitudes, stood in sharp contrast to a more rigid interpretation of Islam adopted by the Taliban and members of groups linked to al Qaeda.