The Islamic State has claimed responsibility for a terror attack on a police training facility in Quetta, Pakistan saying three suicide bombers were responsible for the carnage which left at least 60 dead and another 120 injured.

The militant group said through its propaganda outlet Amaq that it had carried out the attack yesterday evening (24 October). Accompanying the message from Amaq, which styles itself as a news agency, was an image of three armed men wearing suicide belts. One is seen pointing upwards, a typical gesture in IS (Isis/Daesh) propaganda, another has his faced covered.

In the text of the message, which referred to the attackers as "those on a killing spree," IS said the attack had lasted four hours, during which time the militants used their assault rifles and grenades to inflict maximum casualties. They finally detonated their suicide belts when confronted by armed police.

Pakistani authorities said prior to the IS release they suspected the Sunni extremist group Lashkar-e-Jhangvi could be behind the terror attack.

Officials said the attackers received orders from their handlers in Afghanistan just before they launched the attack.

The Lashkar-e-Jhangvi, affiliated with both the al-Qaeda and the Pakistani Taliban in the past, has launched multiple terror attacks on the Afghan-Pakistan border previously.

It has also been said to have links to IS and has been seen simultaneously as a client of the Pakistani Taliban and a rival. Its message is fiercely anti-Shia and it shares the goal of its counterparts in the Middle East of creating an Islamic State.

The information in the IS message has largely been corroborated by information released by Pakistani authorities. The Pakistani Security Services said in a statement three terrorists, all of them were wearing suicide vests, mounted the attack. It added they were in constant touch with their Afghanistan handlers during the onslaught.

The military announced an end to the counterterrorism operation. Helicopters have continued sweeping the area.