U.S.-backed fighters brought in reinforcements into eastern Syria and pushed ahead in their offensive Saturday against local tribespeople, saying that hundreds of pro-government gunmen have joined the worst battles in the region in years.

The clashes that broke out Monday after the Kurdish-led Syrian Democratic Forces detained a former ally who headed an Arab-led faction in the region have left more than 50 people dead and dozens wounded.

Demonstrations in the northern Iraqi city of Kirkuk over the handover of a key facility from federal to local Kurdish authorities turned violent Saturday, and one protester was killed and several were injured, witnesses and local officials said.

Al-Qaida-linked militants attacked an army position in northwest Syria on Friday, killing at least nine government soldiers and wounding others, opposition activists said. There was no immediate word from the government.

The Britain-based Syrian Observatory for Human Rights, an opposition war monitor, said nine soldiers died as well as one of the attackers, who belong to the al-Qaida-linked Hayat Tahrir al-Sham, or HTS, the strongest insurgent group in northwest Syria. It said 12 soldiers and one HTS member were wounded in the attack.

An Iraqi court has sentenced an Iranian and four Iraqis to life in prison for the murder of a U.S. civilian, in a verdict welcomed by Washington.

Stephen Troell, who had been living in Baghdad with his family, was shot dead in unclear circumstances on November 7, officials said.

Hundreds of Syrians protested Friday in the government-held southern city of Sweida, the biggest in a wave of intensifying demonstrations spurred by economic hardship, activists and witnesses told AFP.

The Israeli military on Friday raided a Palestinian town in the northern West Bank, besieging an apartment and sparking a gunfight with local militants that killed an apparently uninvolved Palestinian teacher, his family and Palestinian health officials said. It was the latest in a series of Israeli army raids in the occupied territory that have resulted in a high Palestinian death toll.

Israeli security forces stormed into a town near Tubas, northeast of the Palestinian city of Nablus, and surrounded a house where militants were believed to be holed up. Israeli soldiers called on the wanted militants through loudspeakers to surrender, residents said.

One of Libya's rival prime ministers has rejected the prospect of normalizing relations with Israel days after news broke of a secret meeting between the countries' two foreign ministers.

Last Sunday, the Israeli Foreign Minister Eli Cohen publicly announced that he and Libya's foreign minister had held a private meeting in Rome the previous week, the first ever between top diplomats from both countries.

The United States military has called for an end to days of fighting between rival U.S.-backed groups in east Syria, warning it may help the resurgence of the Islamic State group.

The fighting that broke out Monday — and left at least 40 people dead and dozens wounded in the eastern oil-rich province of Deir el-Zour — was the worst in years. East Syria is where hundreds of U.S. troops have been based since 2015 to help battle IS militants.

Iran accused Israel on Thursday of trying to sabotage its ballistic missile program through faulty foreign parts that could explode, damaging or destroying the weapons before they could be used.

The Israeli prime minister's office declined to comment on the allegation, made in a report aired on Iranian state television. A reporter also said the parts could be used in Iran's extensive arsenal of drones as well.

An airstrike early Thursday hit an alleged drug factory in southern Syria near the Jordanian border, causing damage but there was not word on casualties, Syrian opposition activists said. They said the attack was believed to have been carried out by Jordan's air force.

Jordan's state media reported over the past weeks that several drones carrying drugs were shot down after crossing from Syria.