TRIPOLI, Libya — Libya's Interior Ministry, along with the country's the U.N. ambassador and the commander of the air force, backed a renegade general's offensive against Islamist lawmakers and extremist militias, further building support Wednesday for a campaign the government has described as a coup.

The show of support for Gen. Khalifa Hifter appears to have triggered a heavy backlash.

Libya's navy chief Brig. Gen. Hassan Abu-Shanaq, some of whose units have allied with Hifter, was wounded in an assassination attempt in the capital, Tripoli, early Wednesday, along with his driver and a guard, the official news agency LANA said. The night before, the air forces headquarters in Tripoli came under a rocket attack but no casualties were reported.

Hifter has been leading an armed revolt in perhaps the biggest challenge yet to the country's weak central government and fledgling security forces. He says his campaign, dubbed "Operation Dignity," aims to break the power of Islamists who lead parliament and whom he accuses of opening the door to extremism and fueling Libya's chaos.

Scores of Libyan military units and commanders have made already made loyalty pledges to Hifter's "Libyan National Army" and his offensive, which began Friday, first against Islamist militias in the eastern city of Benghazi. A number of powerful militias also back Hifter, including ones from the western city of Zintan and Benghazi, Libya's second largest city.

Islamists in parliament are backed by other militias, particularly from Misrata, Libya's third largest city.

The myriad militias in Libya — which are split by rivalries and competing agendas — have been the real power in the country since the 2011 ouster and death of Moammar Gadhafi. They are far better armed than the weak police forces or military, which were shattered during the 2011 civil war and never recovered. Their lining up behind Hifter and his opponents runs the risk of an outright conflict between them.

Wednesday's declaration of support for Hifter from the Interior Ministry, in charge of police, appeared to signal a fragmenting in the interim government installed earlier this year by parliament. In a statement posted on its Facebook page, the ministry called on all its forces to join "Operation Dignity," calling it "the will of the people."

"The Libyan police have always been on the side of the people and supports its dreams of building a civil state in which terrorism has no trace," it said.

It was not clear if the statement spoke for the whole ministry or was a sign of splits within it. The post of interior minister has been empty since last year. Because the police forces are so weak, the ministry had to bring a number of militias under its mandate to perform security duties. Some units of the ministry, including the elite Special Forces in Benghazi, had already announced support for Hifter.

A militia umbrella group that backs parliament's Islamists, the Libyan Revolutionaries Operation Room, called on militia fighters working under the Interior Ministry and military to withdraw, calling Hifter's offensive "a military coup aimed only at taking over power."

For the past several days, clashes between pro- and anti-Hifter militias have been taking place near a main camp outside Tripoli where the Operation Room group is based.

Hifter served as army chief under Gadhafi, but was captured by Chadian forces during a disastrous military offensive in that central African nation in the 1980s. He broke with Gadhafi, was released by Chad and lived for years in exile in Virginia in the United States. He joined the National Front for the Salvation of Libya, the country's main opposition group at the time, and in interviews in the 1990s he claimed to be building an armed force with U.S. assistance to "eliminate" Gadhafi and his associates.

He returned to Libya during the 2011 revolt against Gadhafi and briefly served as a commander in its fledging national army after Gadhafi's death. In February, he remerged in Libya via a video, addressing the nation in his military uniform and proclaiming he intended to "rescue" Libya. Authorities described the video as a coup attempt.

He now is trying to rally Libyan frustration with the past three years of chaos and the power of Islamists. On Sunday, his militia allies stormed and ransacked the parliament building in Tripoli, declaring the body suspended. On Tuesday, some lawmakers tried to hold a session at an alternative location to vote on a new prime minister, but came under rocket fire, effectively ending the session.

In a boost for Hifter, Libya's U.N. envoy, Ambassador Ibrahim al-Dabashi, announced his support Wednesday, saying the general's campaign is "not a coup ... but a nationalist move."

Al-Dabashi backed Hifter's demands for the suspension of parliament and for the transfer of all powers to a caretaker government, and he called for Libya to be purged of militias. He urged Hifter and his loyalists not to interfere in politics but to restrict themselves to building cohesive military forces.

The night before, Col. Gomaa al-Abbani, the chief commander of Libya's air force, backed Hifter in a televised address.

Shortly after al-Abbani's speech, several rockets reportedly targeted military bases in Tripoli as attackers looted and set fire to offices belonging to the air force. The explosions rattled residents but there was no word on casualties.

Al-Abbani pledged to make a "new Libya a vital player in combating terrorism and violence," and called on the people to support the military.

The list of Hifter's backers is growing.

The largest political bloc in parliament, which is led by Mahmoud Jibril, Libya's first premier after the civil war that toppled Gadhafi, also threw its weight behind the general. Jibril's group, the National Forces Alliance said in a statement that Libyans have found themselves "drowning in a swamp of terrorism, darkness, killing and destruction."

The group is the largest in parliament but is divided, and Islamists including the Muslim Brotherhood have been able to garner majorities among lawmakers.

Ali Zidan, who was removed from the prime minister post earlier this year by parliament and is now in exile, has also backed Hifter.

Amid the developing crisis, Libya's election commission announced on Tuesday that early parliamentary elections will be held on June 25. There have been mass demonstrations the past months by Libyans demanding new elections after the current body's mandate ran out early in the year.