BEIRUT — Syrian rebels on Monday captured a hydroelectric dam on the Euphrates River in the country's north after days of heavy clashes, carting off boxes of ammunition from defeated regime forces in the latest in a string of recent strategic advances for opposition fighters, activists said.
Also Monday, activists said rebels and pro-government Kurdish gunmen struck a truce to end days of fighting in the town of Ras al-Ayn near the border with Turkey that opposition forces entered earlier this month.
The Britain-based Syrian Observatory for Human Rights said rebel fighters overran regime defenses and captured the Tishrin Dam, near the town of Manbij, before dawn Monday. Observatory director Rami Abdul-Rahman said the dam supplies several areas of Syria with electricity.
"This is a major blow to the regime," said Abdul-Rahman by telephone, describing the dam as "strategic location" on the Euphrates, which flows from Turkey through Syria and into Iraq.
The rebels have scored a series of hard-fought strategic advances recently, perhaps even seizing the momentum in their relentless battle of topple President Bashar Assad's regime. On Sunday, they captured a regime helicopter base outside Damascus before pulling back for fear of government airstrikes.
Amateur videos posted online showed gunmen inside the dam's operations room as an employee sat in front of five screens speaking by telephone about the level of water behind the dam. Another video showed gunman in front of dozens of green wooden boxes apparently full of munitions.
A gunman opened one of the boxes showing that it contained hand grenades. "The Free Syrian Army has fully liberated the Tishrin Dam," one of the rebels could be heard saying.
The activist videos appeared genuine and corresponded to other AP reporting about the events depicted. Syria restricts the access of reporters.
Syria's conflict started in March 2011 as an uprising against Assad's regime, but quickly morphed into a civil war that has since killed more than 40,000 people, according to activists. It has also prompted hundreds of thousands of Syrians to flee to neighboring Lebanon, Jordan, Iraq and Turkey.
Turkey's state-run Anadolu Agency said airstrikes by regime warplanes killed and wounded several people in the Syrian border town Atmeh on Monday. The agency said some of the wounded were brought to Turkey for treatment, and several people were also heading to the Turkish border to seek refuge. Atmeh is about 130 kilometers (80 miles) west of the Tishrin Dam.
Because it is close to the border, Atmeh has emerged as a key smuggling route for aid and arms to rebel areas in the northern provinces of Idlib and Aleppo and as a base for many rebel groups fighting further south. Residents assumed that their proximity to the Turkish border kept them safe from airstrikes.
"This is the first time the jets have hit us here, but it's probably not the last," said Musab Kadour, an Atmeh resident.
A local official in the Turkish town of Reyhanli confirmed that Turkish F-16 jets flew over the border region Monday. He spoke on condition of anonymity because he was not authorized to speak to reporters.
The Observatory reported air raids on other areas as well, including the northern towns of Maaret al-Numan, Kfar Rouma and Harem.
Also Monday, Kurdish activist Mustafa Osso and the Observatory's Abdul-Rahman said the town of Ras al-Ayn has been quiet since Saturday after fighters from the government-leaning Kurdish Democratic Union Party, or PYD, reached an agreement on a truce with rebels, most of them from Islamist extremist groups, including the al-Qaida-inspired Jabhat al-Nusra.
The rebels entered the town earlier this month and have since clashed almost daily with PYD gunmen for control over the area. Both factions add to the complexity of Syria's conflict, which has taken on heavy sectarian — and ethnic — overtones.
The fighting in recent days has left dozens of people killed or wounded, and dozens captured on both sides. Osso and Abdul-Rahman said PYD forces and the rebels agreed to exchange prisoners and to withdraw their militiamen from the town.
Abdul-Rahman said the rival parties agreed to form a local council that will run day to day life in Ras al-Ayn. Osso said thousands of people who fled the town, which has a mixed population including Arabs, Kurds, Chechens and Christians, have started returning home.
A journalist in Ras al-Ayn told The Associated Press that the town has been calm since Saturday, adding that cars with PYD gunmen were seen in the streets with loudspeakers urging residents to return to their homes after the truce was reached. He added by telephone that parts of the town were heavily damaged by government air raids earlier this month.
When regime forces withdrew from Kurdish areas in northeastern Syria in July, they were quickly replaced by Kurdish fighters from PYD. Those forces then battled rebel fighters after they pushed their way into predominantly Kurdish areas. The Kurdish group is affiliated with the PKK, rebels fighting for autonomy in the Kurdish-dominated southeast region of Turkey.
The Islamic militants, who are fighting on the side of the rebels, have played a bigger role in the Syrian conflict in recent months and many openly say they want to set up an Islamic state. The opposition is split, with some groups strongly opposed to the influence of extremists.
The Observatory also said that the health of leading opposition figure Abdul-Aziz al-Kheir, who it said is being held by one of the country's security agencies, has deteriorated recently. It did not disclose details of his health problems.
The National Coordination Body for Democratic Change in Syria accused the regime of being behind the disappearance of two of its leaders, including al-Kheir, shortly after they arrived home from China in September.
Al-Kheir, 61, comes from Assad's hometown of Kardaha and belongs to the president's ruling Alawite minority sect. He spent long periods in jail in the past because of his opposition to the regime.
• Associated Press writer Suzan Fraser contributed to this report from Ankara, Turkey.