About 30 people were killed and more than 50 injured in an explosion outside a police college in Yemen's capital Sanaa, police say.

It was a car bomb that exploded near the college, presumably targeting a group of students standing by the building.

The blast was heard across the city and it resulted in a fire, witnesses told Reuters.

Photographs of the aftermath of the blast have quickly been posted on social media. They show the burning wreckage of the vehicle and bloodied bodies lying on the pavement.

"What happened is we were all gathering and ... (the bomber) exploded right next to all of the police college classmates," eyewitness Jamil al-Khaleedi told The Associated Press. "It went off among all of them, and they flew through the air."

Witnesses said they could see ambulances taking the wounded away from the scene of the blast.

No group has so far claimed responsibility for the attack.

Yemen has seen an increase in instability since the 2011 popular uprising that ousted President Ali Abdullah Saleh.

Al Qaeda in the Arabian Peninsula (AQAP) has been increasingly active, staging a growing number of terror attacks. Neighboring nations are fearing of AQAP gaining enough power to carry out attacks outside Yemen.

At least 33 people were killed in a suicide attack near a cultural center in southwest Yemen a week ago. The attack targeted the Houthi Shiite Muslim militias, who have managed to drive AQAP from many areas they used to control. In November, the AQAP military chief vowed to carry out fierce attacks against Houthi rebels.

Source: rt