The U.K. Guardian on Wednesday published the results of a joint investigation with journalism website Bellingcat and the Lighthouse Reports nonprofit group into Libyan arms sales.

The investigators accused Turkey and the United Arab Emirates (UAE) of committing “increasingly blatant violations of the U.N. arms embargo on Libya.”

The report cited “flight data and satellite images” that appeared to show large military cargo planes from both Turkey and the UAE delivering personnel and equipment to various forces inside Libya. Turkey supports the internationally-recognized Government of National Accord (GNA) based in Tripoli, while the UAE supports the GNA’s adversary Gen. Khalifa Haftar and the House of Representatives (HOR), a rival power structure based in Tobruk.

Libya has been under a U.N. arms embargo since 2011. The Guardian reported a U.N. panel of experts will soon release a similar report on violations of the embargo, which an anonymous diplomat described as “totally ineffective” thanks to “extensive and blatant” violations.

According to the investigation, the UAE conducts regular flights from Qusahwira airport in the Emirati desert to airbases in Egypt near the Libyan border, from which the supplies are ferried by truck or smaller aircraft to Haftar’s troops and allies. 

“The planes travel from a military airbase to military institutions, piloted by the UAE military, eliminating any possibility that their mission is civilian,” the Guardian wrote.

The European Union (EU) also believes the UAE is “likely” sending jet fuel to Libya for military purposes.

Turkey is sending cargo planes from airports in Istanbul, Gaziantep, and Kayseri directly to the Libyan city of Misrata. Social media videos appear to show Syrian fighters allied with Turkey boarding some of these flights, presumably to fight as mercenaries in Libya.

“The Turkish air force used a new route to avoid certain flight information regions. All flights are non-scheduled or special charter flights that attempt to disguise their routes by switching their transponders off,” the Guardian’s diplomatic source said.

The EU angered Turkey in September by freezing the assets of a company called Avraysa Shipping accused of smuggling weapons to Libya. Turkey insisted Avrasya’s vessels were carrying humanitarian aid and claimed Turkish military forces in Libya are now focused primarily on providing humanitarian assistance and cleaning up leftover explosives from the long civil war.

The Guardian’s investigators cited evidence that Russia is also violating the arms embargo by sending combat aircraft to support private military contractors in Libya.

U.N. Secretary-General Antonio Guterres said at a meeting in Germany on Monday that all parties must observe “full and unconditional implementation of the Security Council arms embargo” on Libya.

“The violations of the embargo are a scandal and call into question the basic commitment to peace of all involved. Foreign deliveries of weapons and other military support must stop immediately,” he said.

Ironically, the Guardian quoted analysts who said the flood of weapons into Libya might have produced a bloody stalemate in which all parties have given up on military conquest and developed more of an appetite for negotiations. Guterres expressed hope that talks between the GNA and House of Representatives would move forward, noting that both are undergoing changes of leadership – GNA Prime Minister Fayez al-Sarraj made a surprising announcement in September that he intends to step down at the end of October, shortly after the entire Tobruk-based HOR resigned – so the time for reaching a settlement between the rival governments is ripe.

Delegates from the GNA and HOR met in Morocco on Wednesday for a second round of reconciliation talks, including discussions of how several important national officials and administrators would be chosen. The first round of consultations in September produced an agreement to hold elections within 18 months.

Haftar and his Libyan National Army (LNA) have been pushed back to the city of Sirte. On Saturday, they released two Turkish workers who had been stranded in Sirte when the battle lines shifted. The GNA military said on Saturday that a Russian cargo plane loaded with Syrian mercenaries landed in Sirte to reinforce Haftar’s forces.