“They had planned to make their way into the National Assembly and take the lawmakers hostage to press for their demands,” Mr Hayat said. He said police had arrested up to eight members of the network and a hunt was under way for the rest.

Police paraded the prisoners, Amir Shehzad and Khawaja Ibrahim, before journalists. The suspects had volunteered for a suicide mission and five hand grenades were seized during the arrests.

Mr Shehzad told Reuters on a mobile telephone: “I have been arrested on charges of being a Lashkar-i-Jhangvi member. My friends carried out attacks.” The two men are also suspected of involvement in a suicide bombing that killed 30 people in a mosque in Sialkot on Oct 1.

Last week, security forces caught Abu Faraj Al Libbi, whom United States counter-terrorism officials describe as the third most senior commander in Al Qaeda. More than two dozen other suspects, most belonging to local groups linked to Al Qaeda, have been netted in the days before and after Al Libbi’s capture on May 2.

Al Libbi is being questioned in Rawalpindi. Relevant information was being passed directly to US agents, but contrary to earlier reports they were not part of the interrogation team, officials told Reuters.