DAMASCUS, July 24 (Xinhua) -- A powerful explosion rocked the area around Maarrat Misrin in Syria's northwestern Idlib province on Thursday, killing at least 12 people, including a woman and a child, according to the Syrian Observatory for Human Rights.

The blast, which occurred in an area east of al-Foua and near the town of Sirin, is believed to have originated from a weapons depot, the observatory reported. Explosions continued later in the day as additional ammunition detonated, further complicating rescue efforts.

The Syrian health authorities, quoted by state news agency SANA, reported earlier that seven people were killed and 157 injured in a non-final toll. Many of the wounded are in critical condition. Hospitals across Idlib launched urgent appeals for blood donations, and civil defense teams engaged in retrieving bodies from the rubble.

The observatory noted that the toll could rise, and there were reports of additional casualties. The explosion has caused widespread panic, especially in surrounding displacement camps that house families from across Syria.

Eyewitnesses reported massive secondary blasts, heavy fires, and dense black smoke engulfing the area. Civilian homes, vehicles, and nearby infrastructure sustained damage. Ambulance and civil defense crews rushed to the scene as security forces cordoned off the area, and emergency alerts were issued.

Residents also reported the presence of unidentified aircraft in the sky at the time of the incident, although there has been no official confirmation of any airstrike or foreign involvement.

The cause of the explosion remains under investigation. As of Thursday evening, no group has claimed responsibility, and Syrian interim authorities have not released a conclusive statement on the nature of the blast.