BEIRUT — Syrian rebels captured most of an eastern oil field and stormed a military base in the south, antiregime activists said Thursday, further chipping away at President Bashar Assad’s hold on the country’s hinterlands.
Although Assad’s regime does not appear on the brink of collapse, rebels seeking his ouster have scored a string of strategic victories during the past week, also seizing a large dam and the defenses around a major airport. These blows have shrunk the portion of the nation that Assad effectively governs and may deprive his regime of needed resources.
On Thursday, rebels took the town of Shadadah on the Euphrates River in eastern Syria, and had seized most of the nearby Jbeysa oil field, one of country’s largest, according to the Britain-based Syrian Observatory for Human Rights. The gains came during three days.
Videos posted online in the past three days showed dozens of bearded rebels looting a large red building and making off with boots and green munitions boxes. The bodies of a fewgovernment soldiers were in the dirt nearby.
‘‘These are Assad’s dogs,’’ one fighter said.
Also Thursday, rebels stormed a small military base near the town of al-Sahwa in the southern province of Daraa, near Jordan. The Observatory said at least four fighters were killed in clashes at the base, which rebels had surrounded and shelled for days before launching their raids.
Videos posted online showed rebels chanting in victory as what they said were destroyed tanks burned and sent up columns of smoke in the distance.
All videos appeared to be authentic and were consistent with other Associated Press reporting.
Rebels clashed again with government soldiers for control of the main airport in the northern city of Aleppo and on the east and south sides of the capital, Damascus, activists said.
On Wednesday, rebels stormed an army base near the Aleppo airport and the adjacent Nerab military airport. The fighting has prevented traffic to the airports for weeks.
And earlier this week, rebels captured the nation’s largest dam, a main source of electricity and irrigation for nearby provinces.
Syria’s civil war has posed a dilemma for the international community. While the United States and many Arab and European countries have called on Assad to step down, Russia and China have protected his regime from sanctions by the UN Security Council. Iran also continues to back Assad.
International efforts to push for a negotiated solution have gone nowhere, mostly because both sides still want a military victory.
As the situation inside Syria has worsened, many rebel groups have embraced radical Islamist ideologies and Sunni Muslim foreign fighters have entered the battle, seeing it as a holy war, or jihad, against a regime dominated by Alawites — an offshoot of Shi’ite Islam.
Fighters from the most radical Syrian rebel group, Jabhat al-Nusra, have been at the forefront of most recent rebel victories.
The United States has designated Jabhat al-Nusra a terrorist group, saying it is linked to Al Qaeda in Iraq.
On Thursday, British Foreign Secretary William Hague called Syria ‘‘the number one destination for jihadists anywhere in the world today.’’