Libyan Islamists vow revenge for seizure of Abu Anas al-Libi "We call for targeting any aircraft or vessel related to the Americans and their allies," it added. The basic principle is fighting support for the infidels. Another, by "The Revolutionaries of Benghazi, Al-Bayda and Derna," said: "We condemn this act, and pledge before God to fight those who betrayed their country and involved themselves in this plot. We also say to the Libyan people that we didn't fight against the dead leader to replace him with a traitor or foreign agent who would deliver up our compatriots out of loyalty to the infidels. Benghazi is Libya's second city, and the starting point of the revolution which overthrew Col Muammar al-Gaddafi. Al-Bayda and Derna are two other cities in eastern Libya well-known as bases for militant Islam. Derna was one of the best known recruiting grounds for al-Qaeda under the Gaddafi dictatorship, sending many men to serve with al-Libi and bin Laden in Afghanistan, and later to Iraq. The Libyan government issued a statement on Sunday night denying knowledge of the raid and demanding clarification from the United States for what it also called a "kidnapping." It summoned the American ambassador, Deborah Jones, a further statement said. Justice Minister Salah al-Marghani summoned the ambassador of the United States on Monday morning to ask for answers to several questions relating to the case. However, al-Libi's family said that some of the men who grabbed him, put a bag over his head and bundled him into an SUV outside his house on Saturday were speaking Arabic with Libyan accents. American sources at the time said that the Libyan government had been notified in advance. What central authority the Libyan government ever had has started to break down in recent weeks, with strikes paralysing the oil industry on which it depends for income and militias openly challenging its authority. It fears that being seen to co-operate with or turn a blind eye to an American raid on its territory and the capture of a Libyan citizen will further enrage its opponents. They have already shown themselves able to act with considerable force, for example in the attack on the US consulate in Benghazi a year ago which killed the US ambassador, Christopher Steven, and three others. On Saturday gunmen suspected to be Islamists killed 16 soldiers at a checkpoint near a former Gaddafi stronghold south of Tripoli. Al-Libi himself is now on an American navy ship, the USS Antonio, which was despatched specifically for the task of holding him after his arrest. The US Congress passed a motion after the 9/11 attacks of September 2001 allowing the president wide powers to pursue the "global war on terror." These included the right to authorise the capture of militants abroad and their return to the United States for trial, even if their alleged crimes were not committed on US territory. Officials in Washington say al-Libi, whose real name is Nazih Abdulhamad al-Ruqaie, will be interrogated by members of the "High Value Detainee Interrogation Group." This is an inter-agency group based at the FBI set up by President Barack Obama in 2009 after he banned methods used by the Bush administration to extract information from terror suspects, including "rendition" to third countries and "harsh interrogation methods" such as water-boarding. His first interrogation will be to reveal whatever broader intelligence he can be induced to give up. He will then most likely be interrogated by a second team on the charges against him, at which time he would be read his legal rights. At some point he is likely to be transferred to New York, where he has already been indicted by a court on the bombing charges in his absence. His son, Abdullah al-Ruqaie, told The Telegraph he would most likely refuse to see a lawyer and boycott the legal proceedings. The use of international seizure has been attacked by human rights groups. "The USA has again used its flawed "global war" theory to violate fundamental human rights principles," Amnesty International said in a statement. It demanded he be offered access to a lawyer immediately.