Turkish-backed militias on Saturday attacked a Syrian refugee camp guarded by Kurdish and Arab fighters, an on-scene aid worker said.

“The refugee camp is burning,” said David Eubank, an American whose Free Burma Rangers provide humanitarian relief in war zones. “We are here giving medical help as we can," he told the Washington Examiner. "The Turk/FSA forces are close.”

The Turkish-backed Free Syrian Army attacked the Ein Issa camp, which is guarded by the Syrian Democratic Forces, Eubank and multiple local sources reported.

"Turkish forces launched attacks with tanks, artillery, and a large number of mercenaries on several axis to invade Ain Issa since the morning," the SDF announced on Saturday. "The cease-fire agreement is once again being violated by Turkish army."

Eubank, a former Special Forces officer in the U.S. Army, personally witnessed the attack, he told the Washington Examiner. Four were killed and 22 wounded, including a civilian woman and a young boy, he said.

The American aid worker uses Twitter to describe conditions on the ground in Syria and elsewhere. His tweets on Saturday included a report on the town he described by an alternate spelling, Ein Issa.

“This is a terrible invasion that has not stopped yet,” Eubank said in a video that appears to show an airstrike against the Kurdish fighters defending the camp.

On Nov. 23, Turkish/FSA forces attacked Ein Issa, #Syria. The refugee camp is burning. We’re giving medical help as we can and will report more tomorrow. pic.twitter.com/0KI7ZT7qeH — David Eubank (@DaveEubankFBR) November 24, 2019

The assault took place on the same day that Vice President Mike Pence made a surprise visit to Erbil, the capital of Iraq’s Kurdish region, where he met with Kurdish leaders and addressed U.S. troops.

“The American people will also never forget or fail to honor the service and sacrifice of the brave Kurdish fighters who stood shoulder to shoulder with us in the fight against ISIS,” Pence said Saturday.

The conflict between Ankara and the Syrian Kurds has strained U.S. relations with Turkey, as Defense Secretary Mark Esper and U.S. lawmakers in both parties favor sanctions on the NATO ally. The attack on Nov. 23 against the refugee camp also targeted a key sector of northwestern Syria.

“Ain Issa is also a strategic point to exert influence on the roads into and out of northeast Syria, positioning Turkey to be the ultimate power broker over a large part of Syrian territory moving forward,” Middle East expert Nicholas Heras told Kurdish media.

Fighting at An Issa calmed somewhat on Sunday, reported the Syrian Observatory for Human Rights, a London-based information group.

Within hours of sending the Washington Examiner video footage of casualties being loaded onto a truck bed, Eubank posted to social media photos of gruesome injuries to civilians hurt in the attack.

The Syrian Kurdish fighters, Eubank said, are “holding so far.”