Kurdish fighters have been able to halt the advance of the Islamic State extremist group in the Syrian border town of Kobani, where the U.S.-led coalition has been carrying out airstrikes for more than two weeks, activists said Sunday.

The coalition, which is targeting the militants in and around Kobani, conducted at least two airstrikes Sunday on the town, according to an Associated Press journalist and activists. The strikes, aimed at rolling back the militants' gains, appear to have done little to blunt their assault on Kobani and nearby villages, which began in mid-September.

The Syrian Kurdish border town is the latest focus of the Islamic State group, which has rampaged across northern Syria and western and northern Iraq since the summer, swallowing up large chunks of territory and imposing its reign of terror. Their campaign comes amid the three-year civil war in Syria, where opposition fighters have been battling to overthrow President Bashar Assad.

If Kobani falls, the Islamic State group will control territory abutting Turkey to the gates of Baghdad, some 450 miles (725 kilometers) slicing across Syria and Iraq. The U.S. has been speaking with Turkish officials about increasing their own efforts to equip and train opposition fighters in Syria and U.S. Central Command and European Command will travel to Turkey this week to meet with officials there and discuss the different ways Turkey can contribute.

On Sunday, a Turkish government official confirmed that Turkey has agreed with the U.S. to train 4,000 Syrian opposition fighters. The official said the fighters would be vetted by Turkish intelligence. The official spoke on condition of anonymity because he was not authorized to speak on the record.

In Kobani, the Britain-based Syrian Observatory for Human Rights said Islamic State group militants have not been able to advance since Friday but are sending in reinforcements. The Observatory's chief, Rami Abdurrahman, said the Islamic State group appears to have a shortage of fighters and has brought in members of its religious police known as the Hisbah to take part in the battles.

The Observatory says that since the Islamic State group's offensive on Kobani began, some 550 people have been killed, including about 300 Islamic State fighters, 225 Kurdish gunmen and 20 civilians. It said the number of jihadis killed could be much higher.

Farhad Shami, a Kurdish activist in Kobani reached by phone from Beirut, said the town was "relatively quiet" on Sunday apart from sniper fire. He said Islamic State fighters launched an offensive south of the town Saturday but were repelled and lost many fighters.

"There are large numbers of dead fighters for Daesh who were either killed by the People's Protection Units or the (coalition) airstrikes," Shami said, referring to the main Kurdish force and giving an Arabic acronym for the Islamic State group.

He said Kurdish fighters also were able to regain the border village of Tel Shair west of Kobani.

Abdurrahman said 36 jihadi fighters were killed in Kobani on Saturday. The jihadists control more than a third of the town.

Meanwhile in Beirut, hundreds of Kurds marched through the streets of the city to the U.N. headquarters. They chanted pro-Kurdish slogans and called on the world to help those fighting in Kobani, where more than 200,000 people have fled across the border into Turkey.