[Representational Image] Pakistan Taliban and the Islamic State group have claimed responsibility for the attack. Picture: First responders and volunteers transport the injured and dead away from the scene of a bomb blast outside a hospital in Quetta, Pakistan August 8, 2016.Reuters

A faction of the Pakistani Taliban and the Islamic State group have claimed responsibility for the suicide bombing in a government-run hospital in Quetta on Monday that claimed the lives of at least 70 people and injured over 100 others. The death toll could rise further.

Mourners, most of them lawyers and journalists, had gathered in the emergency department of the Civil Hospital Quetta to accompany the body of a prominent lawyer, Bilal Anwar Kasi, who had been shot dead earlier on Monday.

"The Tehreek-e-Taliban Pakistan Jamaat-ur-Ahrar takes responsibility for this attack, and pledges to continue carrying out such attacks. We will release a video report on this soon," the group's spokesman Ehsanullah Ehsan said in an email to Qatar-based news channel Al Jazeera.

Isis also claimed responsibility for the attack through their news agency Amaq: "A martyr from the Islamic State [of Iraq and the Levant] detonated his explosive belt at a gathering of justice ministry employees and Pakistani policemen in the city of Quetta."

Balochistan Home Minister Sarfraz Bugti was quoted by the channel as saying: "The blast occurred after a number of lawyers and some journalists had gathered at the hospital following the death of Bilal Anwar Kasi, the (former) president of the Balochistan Bar Association, in a separate shooting incident early this morning."

According to Pakistani media reports, journalists, including two cameramen, also died in the attacks. One of the cameramen was Aaj TV's Shehzad Khan. The other was DawnNews' Mehboob Khan who had also worked with Al Jazeera previously.

The hospital area was cordoned off by the police. Pakistan Prime Minister Nawaz Sharif and Army Chief General Raheel Sharif visited the wounded in the hospital.

The United States of America condemned the attack in a statement, which said: "We remain resolute in joining with the people of Pakistan in confronting terrorism in Pakistan and across the region."