LIBYA'S defence minister resigned but then changed his mind and the army chief of staff was sacked, as a political crisis deepened over gunmen besieging government ministries. "I find myself compelled, despite opposition from my colleagues in recent days, to present (my resignation) voluntarily and without hesitation," Mohammed al-Barghathi said, quoted by the official Lana news agency. "I cannot accept the policy of force used by armed groups in our new state," he added. But just hours later, the government issued a statement saying Barghathi had changed his mind after Prime Minister Ali Zeidan asked him to stay on. "The chief of the government asked the defence minister to rescind (his decision) and the minister said he understands, given the circumstances the country is going through, that he should continue in office," a statement said. Separately, members of the National General Congress (NGC), said it had sacked army chief of staff General Yusef al-Mangoush, who has long been accused of delaying the formation of a proper army. Other deputies said Mangoush would stay on for another month until a replacement is named. Militiamen, mostly former rebels who fought to oust Muammar Gaddafi in 2011, have surrounded the justice and foreign ministries since last week to demand the removal from public posts of former officials of the slain dictator's regime. Initially, the gunmen intended to pressure the NGC, the highest authority in the country, to adopt the law on political exclusion. But they remained camped outside the ministries despite the adoption of the legislation, with some of them now calling for the resignation of Zeidan's government. On Tuesday, a dozen vehicles armed with anti-aircraft guns and rocket-launchers were still parked in front of the foreign ministry, an AFP correspondent reported from the site. "We are thuwars (revolutionaries) and we want to correct the process of the revolution," said one of the gunmen who identified himself as Mohamed Ben Neema. The employees and officials of the former regime who massacred the Libyan people continue to occupy important positions, especially the foreign ministry. The revolution has not come to this building.