AMMAN // The Syrian regime has responded to recent rebel gains in the south with a wave of airstrikes of unprecedented accuracy, suggesting precision-guided bombs are being used against western- and Gulf-backed opposition forces.

Dozens of attacks were carried out last week in southern Syria, hitting buildings used by rebels as headquarters for their operations in the region.

On Friday there were 14 airstrikes.

Previous attacks relied on unguided munitions - "old fashioned dumb" bombs, rather than weapons aimed by sophisticated laser or radar targeting - and were largely inaccurate, hitting civilians more often than rebel forces.

They created mass casualties, destroyed homes and spread fear, but were not particularly effective in weakening rebel fighting units.

These latest strikes however accurately hit rebel targets. Two compounds in Al Ajami were destroyed, while others in Yadoudeh, Tafas, Attaman, Tel Shebab and Musajreebn were all hit.

According to sources close to the Military Operations Command (MOC) in Amman, a centre staffed by western and Arab military officials that provides intelligence, weapons and operational support to moderate rebel groups, it was the first time precision weapons have been used by regime forces in such a concerted and successful manner against rebels in the south.

Cruder, unguided weapons, including barrel bombs pushed out of helicopters at high altitude, were also used in the strikes, and were deployed again on Sunday in attacks on the Sheikh Miskeen and Busra al Sham areas.

At least 27 people were killed in the strikes, and 54 wounded, rebel sources said.

Casualties would have been higher, rebels said, if some factions had not evacuated their headquarters after the wave of airstrikes began.

"The regime would often attack our fighters during battles, but attacking [Free Syrian Army] headquarters was not common," a rebel commander said.

Another commander said the coordinated use of such sophisticated weaponry was new on the southern front.

He called it "a means of revenge against civilians and [rebel] military units".

"The regime is now resorting to the harshest measures, but we will not withdraw," the commander said.

Russia, a key backer of president Bashar Al Assad and his principle arms supplier, upgraded several 1980s-era MiG 29 and Sukhoi 24 fighter jets used by the Syrian air force last year, according to sources close to the MOC.

The upgrades equipped the jets with new navigation and weapons systems that appear to have been used infrequently in combat in southern Syria.

RAC MiG, the producer of the Russian-made MiG fighters, has opened an office in Damascus near the Mezze airbase and upgraded at least four MiG 29s to the more advanced 29SM specification, according to the defence analysts Jane's Information Group, citing RAC MiG's 2011 annual report.

The MiG 29SM includes new radar and a wider arsenal of air-to-ground weaponry, including guided bombs, as well as advanced air-to-air missiles.

The last wave of regime air attacks were so accurate that some rebels said they believed them to have been carried out by US-led forces, involved in strikes on ISIL in Syria using laser-guided bombs - much more accurate weapons than those typically used by regime forces.

If newer, precision-guided weapons are now being more widely used by the regime, it would fit a pattern of an escalating proxy war between rebels, backed by the West and Gulf, and the regime, backed by Russia and Iran.

Cautiously, the US has been upping its support for rebels in the south, helping them make gains on the ground against regime forces. More advanced Russian weapons now in use by the regime seem to be directed at reversing those gains and to cut off rebel efforts to establish supply lines to their factions fighting around the capital, Damascus.

"The Iranians and the Russians increased their support to the [Syrian] regime when the US-led coalition started the airstrikes in September," said a defected Syrian air force officer, who monitors developments on the country's southern battlefields.

As well as hitting headquarters, supply depots and an aid warehouse used by moderate brigades linked to the MOC, facilities controlled by the Al Qaeda-affiliated Jabhat Al Nusra were destroyed in Muzaireb. The buildings were evacuated ahead of the strike, however, with Al Nusra fighters in hiding for fear of being bombed by the US-led coalition in its war against Islamic extremist groups.

A headquarters of Harakat Al Muthana, a radical Islamic rebel group that is not linked to the MOC, was also destroyed in a regime air raid.

Civilian houses, not used by rebels, were also hit.

"It was like a horror movie," said one fighter who was close to the bombing of a moderate rebel facility on Thursday.

"I just stopped at the headquarters and a second after I left a missile landed . I saw hands and feet cut off."

Air power has been one of the Syrian regime's principle advantages over lightly armed rebels, in a grinding conflict that has killed more than 190,000, according to UN counts.

Rebels have repeatedly asked their international backers for Manpads, shoulder-launched missiles capable of shooting jets down, but have not been able to secure a regular supply, with Washington concerned the weapons could fall into the hands of Islamic extremist groups, which would then use them against civilian airliners.

foreign.desk@thenational.ae