– At least 67 people were killed and 185 wounded Wednesday in an attack in the northeastern Syrian town of Qamishli, medical sources in the Kurdish-controlled town said.

Rescue teams are still searching for victims under the rubble of the buildings hit by the attack, claimed by the Islamic State in Iraq and the Levant, the sources added.

Earlier reports said that 55 people were killed and more than 160 wounded in what activists said was a powerful blast that rocked Qamishli, which is near the Turkish border.

"The number keeps increasing as lots of victims are still buried under the debris. Many of the injured are listed in critical condition," Qamishli National Hospital Director Omar al-Qaqoub said.

Kurdish news agency Rudaw said the explosion was the result of a double attack. The first was caused by a truck loaded with explosives that targeted a center run by the Kurdish police force.

A second blast hit a street in the east of the town that is home to the local defense administration, Rudaw said.

Rami Abdel-Rahman, the head of the Syrian Observatory for Human Rights, a monitoring group, said the resulting blast was the worst seen in Qamishli.

Syrian state television, meanwhile, aired footage showing extensive damage reportedly from the area where the blast took place.

In the footage, panicking people are seen rushing to help those trapped under the rubble. Women are also seen running and shouting for help.

Qamishli, which is predominantly inhabited by Kurds, has been targeted by recent bombings, many claimed by ISIL.

"An Islamic State fighter managed to reach a number of buildings of the Kurds via his explosives-laden truck, blowing himself up among them … destroying their buildings … killing over 100 and injuring dozens," according to an alleged online statement by the militant group.