Last Updated Oct 13, 2014 4:21 PM EDT
SURUC, Turkey - A suicide bomber from the Islamic State of Iraq and Syria extremist group detonated his explosives-laden vehicle in Kobani on Monday, as fierce fighting with Kurdish militiamen resumed in the northern Syrian town near the Turkish border.
The sound of explosions and occasional gunfire could be heard across the border from Kobani a day after Kurdish fighters managed to slow the advance of the jihadist group. What appeared to be a rocket-propelled grenade struck a minaret in the center of the town, emitting a cloud of white smoke.
Activists said Islamic State of Iraq and Syria (ISIS) militants were carrying out a three-pronged attack from the eastern side of the town and that clashes were ongoing in the southern part.
Later Monday, another suicide attacker blew himself up in a vehicle east of Kobani near the security quarter that houses the main police station and other local government offices, according to the Observatory and Kobani-based activist Farhad Shami.
Shami said the first vehicle appeared to have exploded prematurely. There was no immediate word on casualties from either explosion.
Shami said coalition aircraft flying over Kobani had struck 10 times Sunday and Monday.
On Sunday, the Britain-based Syrian Observatory for Human Rights said ISIS militants had not been able to advance since Friday but were sending in reinforcements. The Observatory's chief, Rami Abdurrahman, said ISIS appeared to have a shortage of fighters and had brought in members of its religious police known as the Hisbah to take part in the battles.
The Observatory says that since ISIS' 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.
The Syrian Kurdish enclave has been the scene of heavy fighting since late last month, with the better-armed ISIS fighters determined to capture the border post.
Kurds are determined not to allow Kobani to fall and are fighting zealously, but they have struggled to curb advances by the more heavily armed extremists.
On Friday, the militants seized the so-called Kurdish security quarter - an area in the town's east where Kurdish militiamen maintain security buildings and where the police station, municipality and other local government offices are located.
The extremist group has carved out a vast stretch of territory from northern Syria to the outskirts of Baghdad and imposed a harsh version of Islamic rule. The fighters have massacred hundreds of captured Iraqi and Syrian soldiers, terrorized religious minorities, and beheaded two American journalists and two British aid workers.
A U.S.-led coalition has been carrying out airstrikes against militant targets in and around Kobani for more than two weeks, and the town's fate has emerged as a major test of whether the air campaign can roll back the extremists in Syria.
The Observatory said an ISIS suicide bomber detonated a car filled with explosives in the northern part of Kobani near the border with Turkey on Monday.
It said the car was headed to the border crossing between Kobani and Turkey. A Kurdish activist in the town, Farhad Shami, said the vehicle appeared to have exploded prematurely. It was not immediately clear whether there were any casualties.
Shami said coalition aircraft were flying over Kobani and had struck 10 times Sunday and Monday.