Pakistan’s military says it foiled a plot to free British-born militant Ahmed Omar Saeed Sheikh, currently on death row for the 2002 murder of Wall Street Journal reporter Daniel Pearl.
Three Islamist militant groups were working together on the plan, said army spokesman Lt General Asim Bajwa.
Six suicide bombers were to be involved in the plot, which was close to being carried out, he said.
Pearl was kidnapped by militants from Karachi and beheaded four months later.
The groups involved in the plot to spring prisoners from Hyderabad Central Jail were al-Qaeda, the Pakistani Taliban, and Lashkar-e-Jhangvi (LEJ), Lt Gen Bajwa said.
The army had arrested 97 militants from the groups over the past two years. They are accused of attacks on two Pakistani air bases, Karachi airport and several other targets.
Among them were three commanders, the army spokesman said. The LEJ’s Naeem Bokhari and Sabir Khan, and Farooq Bhatti, deputy chief of al-Qaeda in the Indian Subcontinent (AQIS), were reportedly captured by Pakistani forces in recent raids.
“Our conclusion is that all of the terrorist groups are trying to co-operate with each other in order to carry out terrorist attacks,” Lt Gen Bajwa told a news conference.
Several of those arrested, including Naeem Bokhari, were in the advanced stages of planning the jailbreak, he added.
Video images released by the army showed blue plastic barrels filled with explosives, washing machines that had been used to transport arms and ammunition, long lengths of detonating cord and dozens of ball bearings.
The footage also showed several rifles that Bajwa said had been stolen from police in earlier targeted attacks.
“This plan was 90% ready for execution,” he said.
Saeed Sheikh, who kidnapped and killed Pearl, is being held at the jail.
Lt Gen Bajwa said more than 350 kg (772 lb) of explosives had been recovered from a building believed to be a hideout.
Lashkar-e-Jhangvi’s ideology is closely aligned with the so-called Islamic State, and the group once enjoyed the backing of Pakistan’s powerful spy agency, the Directorate for Inter-Services Intelligence (ISI).
Deadly recent attacks in Pakistan
- 20 January 2016: Militants kill at least 19 people in attack on Bacha Khan University in Charsadda, near Peshawar
- 13 December 2015: Bomb blast kills 24 people at a clothes market in the Kurram tribal region
- 18 September 2015: Taliban militants kill 29 people in an attack on an air force base in Peshawar
- 13 May 2015: Gun attack on a bus carrying Ismaili Shia Muslims in Karachi leaves at least 45 people dead
- 13 February 2015: Militants attack a Shia mosque in Peshawar with guns and grenades; at least 20 people killed
- 30 January 2015: Bomb blast at a Shia Mosque in Shikarpur district, Sindh province, kills at least 40 people