Acting independently of their American allies, Egypt and the United Arab Emirates twice carried out airstrikes against Islamist militias in Libya in the last week, officials told The New York Times.

The United Arab Emirates, among the wealthiest in the region and commanding a formidable air force that includes American F-16s and French Mirage fighter jets, carried out attacks in the vicinity of Tripoli, according to the diplomats, destroying military vehicles, rocket launchers and weapons depots.

Egypt, situated midway between the Arab Gulf state and Tripoli, provided bases for the strikes.

Egyptian president Abdul Fatah Sisi, the former army leader who took office in June after removing the Islamist Mohamed Morsi from power a year earlier, denied on Sunday that his country directly participated in the attacks. “There are no Egyptian aircraft or forces in Libya and no Egyptian aircraft participated in military action inside Libya,” he said.

However, according to American officials, special forces, primarily composed of Emiratis, also operated out of Egypt and managed to destroy an Islamist camp near Libya’s eastern city of Derna.

The involvement of Egypt and the United Arab Emirates underlines the continued instability in Libya since a rebellion, supported by airstrikes from NATO countries and the Emirates, toppled autocrat Muammar Gaddafi in 2011. Transitional authorities in Tripoli have struggled to assert themselves, especially in the east and south of the country where independence movements have sprung up. Former rebels who defeated Gaddafi’s army have refused to disarm, carving out fiefdoms of their own that are vulnerable to traffickers and terrorists who use the Libyan desert as a transit route and a staging ground for attacks elsewhere in the region.

A retired Libyan military general, Khalifa Belqasim Haftar, launched a private campaign against Islamist rebel groups earlier this year, setting off the latest round of fighting.

Haftar, who was a colonel in Gaddafi’s army, fell out with the former strongman after his 1987 defeat in Libya’s war against Chad. He later moved to the United States where it is believed he was trained by the CIA.

The Egyptian-Emirati initiative also underlines the growing conflict between conservative Sunni regimes that seek to restore the status quo in the Middle East and Qatar and Turkey which have backed Islamist revolutionary movements instead.

According to the officials who spoke to The New York Times, Qatar provided weapons to the Islamist fighters in Libya. It earlier backed the Muslim Brotherhood in Egypt following the removal of longtime president Hosni Mubarak in early 2011.

Mubarak’s resignation led to an estrangement between Egypt’s ally the United States, which initially supported the revolution in the country, and other conservative Sunni states, especially Saudi Arabia. The latter were also alarmed by President Barack Obama’s diplomat outreach to Iran, fearing that he might reach an accommodation with their nemesis to reduce American involvement in the region.

The monarchies in the Persian Gulf, with the exception of Qatar, rushed to support Egypt’s military when it removed the Muslim Brotherhood from power while the Americans suspended some of their military support in protest to the coup.

Sisi on Sunday claimed Qatar and Turkey were spending “hundreds of millions of dollars to spread chaos among the Arab nation, destabilizing Egypt and destroying the Egyptians” — an unusually candid accusation from a Middle Eastern leader and highlighting the deep level of mistrust between states that are all nominally allies of the United States.