A suicide bomber in Pakistan killed at least 70 people and wounded more than 100 on Monday in an attack on mourners gathered at a hospital in the southwestern city of Quetta, and Islamic State and a Taliban faction claimed responsibility.

The bomber struck as a crowd of mostly lawyers and journalists crammed into the emergency department to accompany the body of a prominent lawyer who had been shot and killed in the city earlier in the day, Faridullah, a reporter who was among the wounded, told Reuters.

Abdul Rehman Miankhel, a senior official at the government-run Civil Hospital, where the explosion occurred, told reporters that at least 70 people had been killed, with more than 112 wounded.

“There are many wounded, so the death toll could rise,” said Rehmat Saleh Baloch, the provincial health minister.

Islamic State’s Amaq news agency reported the Middle East-based movement was behind the atrocity. If true, it would mark an alarming development for Pakistan, long plagued by Islamist militant violence but most of it locally-based.

“A martyr from the Islamic State detonated his explosive belt at a gathering of justice ministry employees and Pakistani policemen in the city of Quetta,” Amaq said.

Jamaat-ur-Ahrar, a faction of the Islamist militant Pakistani Taliban group, earlier said it had carried out the attack. The movement at one time swore fealty to Islamic State’s Middle East leadership, but later switched back to the Taliban.

“The Tehreek-e-Taliban Pakistan Jamaat-ur-Ahrar (TTP-JA) takes responsibility for this attack, and pledges to continue carrying out such attacks,” said spokesman Ehsanullah Ehsan in a statement.

Only last week, Jamaat was added to the United States’ list of global terrorists, triggering sanctions.

It remains unclear what ties Jamaat retains to Islamic State, whose leadership is a rival to both the Taliban and al Qaeda over claims to represent the true Islamist Caliphate.