SOUTHERN SYRIA — A few years ago, the Islamic State group dominated vast swaths of Iraq and Syria, but thanks to the US-backed Syrian Democratic Forces (SDF), the terror group is now clinging to a tiny piece of land in Bagouz, Syria.

Despite the Islamic State's losses, the terrorists pose a deadly threat to Syrian civilians in the area.

A spokesman for the Syrian Democratic Forces fighting the militants told the Associated Press Sunday that the group is preventing Syrian families from leaving the frontlines of the conflict, closing a corridor from which nearly 40,000 residents have managed to escape since December.

Trapped civilians are risking their lives to leave the last ISIS stronghold. On Tuesday, some 40 men, women, and children fled Bagouz in an effort to reach the nearest refugee camp.

The refugees are forced to walk dozens of miles in the Syrian desert with no food, water, or shelter. There to meet them is a small group of Christians called the Free Burma Rangers.

"There are an unknown number of civilians trapped in a tent city on the southeast edge of Bagouz. ISIS fighters are amongst them and do not let people flee," David Eubank, founder of The Free Burma Rangers, told CBN News on Tuesday. "We pray that all can break free."

"People are shot as they try to escape and the families who got out today said they had been trying for weeks to flee. They were able to bribe a guard and sneak out last night and hid until this morning when they walked to SDF lines. "We were told we would be killed if we tried to escape and even if we made it, the enemy (SDF) would kill us. But we were desperate and so we ran away and now we see you all help us and are kind and do not kill us. Thank you, thank you ."

The Free Burman Rangers have been working in Syria since 2015.

"We fed and gave medical treatment and blankets to these families and pray for the others still trapped. ISIS holds very little ground but as they are in amongst the IDPs (internally displaced persons) it is hard to rescue the families. The SDF are doing their best to find a solution. Complicating the issue is the fact that almost all these families are ISIS families and some still believe the ISIS cause is just. So we are careful when we meet them and bring them up to the collection point but overall we pray and ask for God's love to work through us to them," Eubank explained.

The Christians share Jesus with the refugees and urge the ones who are loyal to ISIS to turn their backs on the terror group.

"'The way of ISIS, the way of hate is over' we tell them," he explained. "'Yes, there are injustices but ISIS will never give you justice. It is the wrong way. Ask God for a new way and be thankful you are alive and that the SDF are merciful to you.'"

"We pray with them and with the help of the SDF do our best to help them. The SDF are trying to negotiate to get all the people out of the Bagouz stronghold," Eubank said.

President Donald Trump announced in December that ISIS is nearly defeated and he will pull US forces out of the region.

However, US defense officials warn that the group still poses a major threat and could regroup within six months if pressure is not kept on them.