By Sarah Dadouch

BEIRUT (Reuters) - With relative calm in southwest Syria since a ceasefire was reached in early July, civil defense services in rebel-held Deraa have shifted focus to clearing unexploded cluster bombs left by air strikes.

Men in light blue vests set up yellow tape around any of the small, silver winged cylinders found, alongside red signs marked with skeleton symbols reading, "Danger! Unexploded ammunition!"

A specialist civil defense team, trained last year in Jordan to clear mines, has dealt with about 100 cluster bombs in Deraa and nearby villages this week alone, a team member said.

After the tape and signs are set up, rescue service members pile bags of dirt around the cluster bomb and place their own blue-and-white explosive cylinder inside, a red wire trailing from it.

The team, in protective gear, hide behind mounds of soil or buildings. One man holding a trigger attached to the red wire warns his colleagues by radio. Then a shower of dirt and rubble erupts, leaving one fewer unexploded bomb on Deraa's streets.

"We faced a lot of difficulties from air strikes and bombs in open areas," Hasan Fashtaki, a member of the unexploded ordnance team, told Reuters by phone. "But now because of the ceasefire and calm in the area, we're working freely," he added.

Deraa is located in a "de-escalation zone" agreed by the United States, Russia and Jordan as part of Washington's first peacemaking effort in Syria under President Donald Trump after six years of civil war.

It has protected Deraa and surrounding areas from new bombardment, allowing the civil defense to focus on unexploded bombs, according to Fashtaki.

The team spent 20 days in Jordan in October training and learning to de-mine areas. Bombs have been concentrated in areas that suffered heaviest bombardment including front lines and the southwestern village of Horan, Fashtaki said.

He did not know how many more unexploded bombs there were in the area or how long it will take to clear them.

"It could be that in two or three or four months time, we still would not have finished our work."

(Reporting by Sarah Dadouch; editing by Mark Heinrich)