– In a rare strike in the heart of Pakistan's capital militants killed at least 11 people at the district court complex on Monday, shaking the government just as prospects for talks with the Taliban seemed to be improving.

An obscure militant cell, calling itself Ahrar-ul-Hind and thought to be a ­splinter group from the Pakistani Taliban, claimed responsibility, just a day after the Pakistani government announced that it would halt airstrikes against Taliban militants who had declared a cease-fire. But the group gave no motive for the attack.

A senior judge, Rafaqat Ahmed Awan, was among those killed in the assault, carried out by gunmen with explosive vests who also wounded at least 25 people and set off a chaotic mass rush from the court complex and a busy market nearby, police officials said.

Emergency meeting

Afterward, Prime Minister Nawaz Sharif held an ­emergency meeting with the army chief, Gen. Raheel Sharif, and the head of the Inter-Services Intelligence directorate, Lt. Gen. Zahir ul-Islam.

Shahidullah Shahid, a spokesman for the Pakistani Taliban, denied any role in the assault on the court complex.

"We have nothing to do with the attack," he said in a telephone interview. "We have announced a cease-fire, and we will follow it for one month. Media should restrain itself from blaming us."

Witnesses described scenes of chaos after the attackers suddenly opened fire around 9 a.m. Monday.

The number of attackers remained unclear. Police officials said there were only two gunmen, but witness accounts, and later comments by senior security officials, suggested that there could have been three or four.

Hubdaar Shah, who works as a clerk in a lawyer's office, said he was coming out of a judge's office when he heard gunshots.

"I ignored the first gunshot sound and kept walking toward my office, but then the gunfire got louder and started coming from two different directions," Shah said. "The gunfire continued for several minutes. Then, we heard two small explosions, followed by a big explosion."

"There was confusion as we did not know what was happening. Everyone was running for cover," he said. "Nothing like this had ever happened before. It was a frightening experience." Shah said he escaped the gunfire by taking a narrow street between the law offices and courts.

Soon after, police officers and troops arrived, cordoned off the area, and combed through the offices to search for the attackers and secure buildings. Sikandar Hayat, police chief of Islamabad, told reporters that the attackers detonated their explosives after they had been surrounded by the police.