QUETTA, Pakistan — Weeping relatives gathered Sunday to identify the charred remains of loved ones killed in a double attack in Pakistan's troubled southwest claimed by a banned Sunni militant group.

At least 25 people were killed on Saturday when militants blew up a bus carrying female students in Quetta, capital of restive Baluchistan province, and then stormed a hospital where survivors had been taken for treatment.

The extremist sectarian outfit Lashkar-e-Jhangvi (LeJ), responsible for a string of outrages against Pakistan's Shiite Muslim minority, said it was behind both attacks.

An LeJ spokesman said a female suicide bomber struck the bus — a rare tactic in Pakistan — before gunmen attacked the hospital, claiming the strikes were revenge for an operation by security forces earlier this month.

Militants occupied parts of the Bolan Medical Complex in a standoff that lasted several hours and ended when security forces stormed the building, freeing 35 hostages.

Authorities shut down the hospital on Sunday, moving patients to another facility, as investigators combed the grisly aftermath of the violence.

The intensity of the blast and subsequent fire reduced the student bus to a blackened skeleton, and outside the mortuary of the Provincial Sandeman Hospital on Sunday, weeping relatives gathered to identify bodies amid a strong stench of burnt human flesh.

The state of the bodies added confusion to the relatives' burden of grief as some were given contradictory information about their loved ones.

Mohammad Hamza, 19, said that on Saturday he had been given the body of his student sister, only to be told a mistake had been made.

"I came here after someone had given us the information that we had taken the wrong body and my sister's body was still here at hospital, but it is not true," Hamza told AFP. It appeared the body he was given on Saturday was indeed his sister.

Mohammad Yasir, deputy registrar of Sardar Bahadur Khan Women's University, said DNA testing may be needed to identify many body parts.

LeJ spokesman Abubakar Siddiq called newspaper offices in Quetta late Saturday to claim the killings.

"The suicide attack on the bus was carried out by one of our sisters. She boarded the student bus and blew herself up," Siddiq said.

"Then we carried out a second suicide attack at the hospital and our fighters killed several people. We did this because security forces killed our fighters and their wives in Kharotabad."

Pakistani security forces on June 6 killed at least three militants and two women during a raid at a house in the Kharotabad neighborhood of Quetta. Officials said they belonged to Tehreek-e-Taliban Pakistan, with whom LeJ has links.

The attacks came hours after a national monument linked to Pakistan's founding father Muhammad Ali Jinnah was destroyed by separatist militants in Ziarat town, 50 miles southeast of Quetta.

Quetta is a flashpoint for sectarian violence between majority Sunni Muslims and minority Shiites, who account for 20 percent of Pakistan's 180 million population, and the city saw the country's two bloodiest attacks so far this year.

A giant bomb planted in a water tanker being towed by a tractor killed 90 Shiite Hazaras in February, while another suicide bombing at a snooker club in January killed 92 others. Both were claimed by LeJ.

There was fury in the Pakistani press on Sunday, both at the perpetrators and the security forces for failing to prevent the third major atrocity in Quetta in six months.

Dawn, the country's leading English-language newspaper, said the state's shortcomings had been shown once again.

"That the state has again failed both at the level of intelligence-gathering and preventing a terrorist attack from succeeding is also obvious," it said in an editorial.

"Unhappily, the more obvious these truths, the less likely it seems that anything will be done to address them."

Sardar Bahadur Khan Women's University is located close to a Shiite Hazara neighborhood in Quetta, and many Hazaras are students.

Baluchistan, which borders Iran and Afghanistan, is rife with Islamist militancy and a regional insurgency waged by separatists demanding political autonomy and a greater share of profits from the region's natural resources.