CAIRO — Just two days after rebel Libyan commander Khalifa Hifter declared a “final” and decisive battle for the capital Tripoli, heavy fighting raged for a 24-hour period between his troops and militias loosely allied with the internationally backed government based in the city, officials said Saturday.

The fighting came after Hifter, the leader of the self-styled Libyan National Army, said Thursday that the “zero hour” of his battle for Tripoli had begun, nearly eight months after he began an offensive to take the city from the country’s Government of National accord supported by the U.N.

The LNA’s media office shared images of reinforcements arriving in Tripoli, including ground troops and pickup trucks with mounted machine guns and of clashes in southern parts of the city. Hifter’s forces took control of the town of al-Tawghaar, just south of Tripoli, the LNA said. But Tripoli-based forces disputed that claim.

The fighting has threatened to plunge Libya into another bout of violence rivaling the scale of the 2011 conflict that ousted and killed longtime dictator Moammar Gadhafi.

In the chaos that followed Gadhafi’s death, the country was divided into two parts — a weak U.N.-supported administration in Tripoli and a rival government in the east aligned with the LNA.

The LNA’s media office said it shot down a Turkish-made drone over the town of Ain Zara south of the capital. Hifter forces captured a major military camp from the Tripoli-allied militias and clashes continued around the camp, officials from both sides said.

The LNA also launched airstrikes overnight against an air base at the Air Force Academy in the city of Misrata, targeting military warehouses allegedly housing Turkish-made drones used by Tripoli-allied militias, said LNA spokesman Ahmed al-Mesmari.

Misrata, in western Libya, is the country’s second largest city and is home to fierce militias who oppose Hifter and have been extremely important in the government’s defense of Tripoli.

There was heavy fighting elsewhere around Tripoli in the new push by Hifter’s forces and officials on both sides said the latest offensive has been more intense than Hifter’s other offensives over the past eight months.

Since his troops marched toward Tripoli in April, Hifter has only been able to lay siege to the city, failing to claim it from the government of Prime Minister Fayez al-Sarraj.

In past months, battle lines have barely changed, with both sides dug in and shelling each other in the southern capital’s reaches. Both sides have also sought support from regional and international backers.

U.N. experts said in a 376-page report to the U.N. Security Council this week that Jordan, Turkey and the United Arab Emirates are supporting Libya’s warring sides and have “routinely and sometimes blatantly supplied weapons, with little effort to disguise the source” in violation of a U.N. arms embargo.

Hifter is backed by the United Arab Emirates and Egypt, France and Russia. The Tripoli-based government receives aid from Turkey, Qatar and Italy.

Libyan and U.S. officials have accused Russia of deploying fighters through a private security contractor, the Wagner Group, to key Libyan battleground areas in recent months.

While Moscow has repeatedly denied any role in the fighting in Libya, the Government of National Accord said it has documented between 600 and 800 Russian fighters in Libya fighting with Hifter forces.

“The Russian fighters’ toughness, lethal techniques and coordination discipline have instilled fear in the anti-Hifter forces,” said Jalel Harchaoui, a Libya expert at The Netherlands Institute of International Relations. “Now, Hifter and all foreign states backing him have become dramatically more confident that Hifter’s brigades will enter Tripoli within the foreseeable future.”

The U.N. experts’ report also said the presence of Chadian and Sudanese fighters in Libya “has become more marked” in 2019 and said they represent “a direct threat” to the country’s security and stability.

Hifter’s declaration of his most recent offensive came after the signing of a security arrangement and maritime deal between Sarraj’s government and Turkey last month.

The maritime deal would give Turkey access to a Mediterranean Sea economic zone offshore from Libya. Cyprus, Egypt and Greece claim the accord violates international law.

The deal has also added tension to Turkey’s ongoing dispute with Greece, Cyprus and Egypt over oil and gas drilling rights in the eastern Mediterranean.