TRIPOLI, Libya - Libya's military banned flights Saturday over the eastern city of Benghazi, a day after troops loyal to a rogue general attacked Islamist militias in violence that killed 51 people, authorities and medical officials said.
The North African nation's weak central government already described the offensive Friday by Gen. Khalifa Hifter, which included military air support, as tantamount to a "coup." And as militiamen reported a separate helicopter attack on one of their bases Saturday, the violence again showed how precarious government control remains after the 2011 civil war that toppled dictator Moammar Gadhafi.
In a statement, the Libyan military's central command said it will target any military aircraft flying over Benghazi, where the country's uprising against Gadhafi began. The city's airport remained closed Saturday for a second day, though stores reopened.
Despite government warnings, Hifter vowed to press on with his campaign in Benghazi to restore security, charging that the current interim Cabinet has no mandate. In comments to the press aired on television, Hifter said: "Today is the start of a national battle. It is not a coup, it is not a quest for authority."
He added: "All Libyan blood is sacred but the terrorism and its servants wanted a battle."
Hifter's forces withdrew to the city limits after attacking the bases of two Islamist militias, Rafallah al-Sahati and February 17. Libya's Health Ministry said Saturday that the offensive killed 36 people and wounded 139. Medical officials in Benghazi later said the death toll had climbed to 51.
Other militias, including the hard-line Ansar al-Shariah group, also were targeted in the clashes.
Hifter's offensive, apparently backed by some federal troops, comes amid rising violence in Benghazi blamed on powerful Islamist militias acting outside of government control. Hifter's spokesman said his offensive aimed to bring these militias under government control and end lawlessness in the city.
Speaking Saturday on local television station Libya Awalan, Hifter's spokesman Mohammed al-Hegazi urged residents of several Benghazi neighborhoods to leave their homes to avoid getting caught in future fighting as they prepare for further operations there. He said the operation against the militias will continue "until Libya is cleansed" of extremists.
By late Saturday, residents of Benghazi said some civilians fled their homes over the warnings.
In response, the Islamist al-Sahati militia issued a statement warning residents of the neighborhoods near Hifter troops to flee before their own offensive.
Mohammed Boqoffa, a spokesman for February 17, told a local television station Al-Nabaa that a military helicopter attacked a militia base Saturday, but wounded no one. Another February 17 spokesman named Ali Mohammed told the station that Hifter's troops illegally controlled the city's military air force base.
Hifter's spokesman denied there was an attack Saturday, saying the helicopter only flew a reconnaissance mission.
In a statement Saturday night, Libya's interim prime minister, parliament speaker and the head of military warned Hifter against further pursuing his offensive and threatened troops cooperating with him.
The joint statement, read by the head of the Libyan Parliament, Nouri Abu Sahmein, accused Hifter of using the rise in violence in Benghazi to "pursue personal gains or turn against the state legitimacy." He also said Hifter is wanted by the country's military prosecutor.
"We call on Benghazi residents, the city of the revolution, to be steadfast and be united ... to get rid of those leading the coup and to protect the city," Abu Sahmein said.
Later Saturday, security officials said gunmen killed a prominent cleric who preaches in a mosque affiliated with Ansar al-Shariah. The official spoke on condition of anonymity because he was not authorized to speak to journalists.
The central government and parliament are already weakened by a recent dispute over naming an interim prime minister between Islamist and non-Islamist politicians. Many in the country are divided over the offensive, having grown impatient with the central government's inability to rein in the militias or govern. Last week, three protesters were killed during a protest outside the base of one of the militias. The incident led Libya's justice minister to ask February 17 to abandon its base. The militia ignored the request.
Those in Benghazi, considered the heart of Libya's oil-rich eastern region, long complained that Gadhafi's government starved it of resources during his 42-year rule. Since his ouster, militias rooted in the rebels that fought him have become the real power in Libya, including increasingly radical groups taking hold in Benghazi.
The past two years, militias have killed some 200 prominent figures, including top police officials, prosecutors, judges and activists, mostly in the country's east. A Sept. 11, 2012, attack there killed four Americans, including U.S. Ambassador Chris Stevens.
"The problem is we don't have a central command or a government to begin with. They are sitting in one room in Tripoli that they can't even protect," said Essam al-Jahani, a political analyst in Benghazi. "The residents of Benghazi need help from anyone. There are honorable people who joined Hifter."
Hifter, who once headed the army under Gadhafi but defected in the 1980s, had been assigned to help rebuild the country's military, but he was removed soon after. He appeared in an online video in February and proclaimed he intended to "rescue" the nation. Authorities described his declaration as a coup attempt.