Qatar, with help from the US, is training Syrian rebels at a base in the desert to fight President Bashar Assad’s forces and the Islamic State group.

Most of the rebels trained at the camp fight under the umbrella of the Free Syrian Army — the largest opposition force in Syria, but some may also be affiliated with extremist organizations that the US has sworn off.

The camp in Qatar lies south of the capital between Saudi Arabia’s border and Al Udeid, which is the largest US air base in the Middle East.

Reuters reported that the suspected location of the camp is a closed military zone guarded by Qatari special forces.

According to the report, Qatar has been training rebels from the northern part of the country for nearly a year, but the program has not produced any significant impacts on the battlefield.

The report is the first indication that Qatar is involved in an official train-and-equip program for moderate Syrian rebels.

For years, Qatar has been accused of supporting extremist groups in Syria such as Jabhat al-Nusra, but no concrete evidence has been uncovered.

In spring 2013 the US selected groups of moderate rebels fighting with the Free Syrian Army through a classified CIA-led program. The program allowed for the transfer of U.S.-made weapons to Turkey via other countries’ aircrafts. The weapons were then driven into Syria by truck. The program was partially funded by Saudi Arabia and other wealthy Sunni states. It is unclear if the training camp in Qatar is part of this CIA program.

The U.S. ramped up efforts to support the moderate opposition later in the year and began training several thousand rebels at a secret base in Jordan. Since then, the rebels have failed to make any significant advances in Syria. In fact, they lost Homs, once dubbed the “heart of the revolution,” to the regime in May.

That CIA program is merging with one that is going to be facilitated mostly by the U.S. Department of State. But the Department of Defense, Free Syrian Army soldiers have always been involved in the train-and-equip program. They have worked with the CIA since the program started in 2013, the sources said.Residents arrive on foot to inspect their homes in Homs on May 14, 2014. The fall of Syria’s third largest city to government forces was a major blow to the opposition and a boost for Assad.

IBTimes reported last week that the US had begun the process of withdrawing its support for rebel groups in northern Syria after they suffered major losses to extremist groups in Idlib province. The Syrian Revolutionaries Front and Harakat Hazm, both of which fight under the umbrella of the Free Syrian Army, are two major beneficiaries of the U.S. weapons program in Syria.

Both groups have suffered major losses over the past several weeks in Syria, overrun by Islamist militant groups such as Jabhat al-Nusra. Syrian opposition members affiliated with the groups, some of whose spokesmen requested anonymity, said US weapons shipments have stopped.

It is unclear from the Reuters report if the Qatari camp will remain part of the US future effort to train and equip moderate rebels in Syria.