ZAATARI REFUGEE CAMP, Jordan - The flow of Syrian refugees into Jordan has increased sharply over the past few days amid fears the Assad regime will use chemical weapons in a final desperate blow against the rebels.

The United States has said it might intervene if Damascus uses chemical weapons in the civil war; in recent days American transport planes carrying military equipment have reportedly landed at Jordanian airports.

Back on the border, thousands of refugees continue to pour into Jordan.

Faisal Abu Dahlush, a farmer from the village of Tafas in south Syria, arrived at Jordan's Zaatari refugee camp Saturday with 14 family members after being smuggled across the frontier by the Free Syrian Army.

"We're afraid of the regime's final offensive. Because the army fired Scud missiles, we think they're going to use chemical weapons. We stayed in the village until now to farm our land, despite all the shelling and shooting. But we can't take the risk of staying with our women and children if they fire chemical missiles," he said.

"There were army roadblocks at the entrance to every village and on the roads until a few weeks ago. Now, because of the rebels, the army moves in larger numbers, firing hundreds of shells on the villages. In some cases they even used phosphorous bombs."

Akram, a farmer from the village of Samad who arrived at the camp over the weekend, said that "until now we held on, but in the past few days they've shelled the village incessantly. Every day people have been killed. The Free Syrian Army helped us flee to the border, and from there the Jordanian army brought us to the camp."

There are no precise figures on the number of Syrian civilians who have fled over the 22 months of civil war, but international aid agencies and neighboring governments estimate that more than 400,000 refugees are now in Jordan, Turkey and Lebanon.

The Zaatari camp opened five months ago about five kilometers south of the Syrian border. Run by the Jordanian government with the aid of the UN refugee agency, it is one of the largest refugee centers for Syrians, currently housing more than 32,000 people.

Yesterday, aid workers were setting up hundreds of additional tents to accommodate the next wave of refugees.

Suleiman, a Syrian who before the civil war drove passengers to Jordan, Iraq and Saudi Arabia, said he had been staying in the Syrian border town of Ramta for 15 days.

"I'm afraid to return because the army is stopping people on the road and shooting anyone they don't like the look of," he said. "The army no longer controls the villages and towns in the area; they're afraid of the Free Syrian Army, especially at night. Entire battalions of the Fifth Division wander around, attacking a village or two a day with tanks and guns, destroying everything they come across."

U.S. forces are already operating in Jordan, officially for training the Jordanian army and Palestinian security forces. In recent months the Americans have reportedly beefed up these forces to help the Jordanians prepare for chemical warfare in their territory.

If American forces operate against the Assad regime, Jordan is expected to serve as an operation base for special forces that enter Syria and take over chemical weapons.

The American magazine The Atlantic has cited senior Jordanian officials as saying Israeli requests to enter Jordan to operate against Syria's chemical weapons have been turned down.

Open gallery view The entrance to the Zaatari refugee camp in northern Jordan, December 16, 2012. Credit: Zarlasht Halaimzai