A series of explosions rocked the city of Bata in the central African nation of Equatorial Guinea on Sunday, killing at least 20 people, news reports said, and injuring untold more.

The Reuters news agency quoted a local television station, TVGE, as saying that at least 20 people had been killed. A local news outlet, TVGE, said hospitals were reporting as many as 400 were injured.

The cause of the blasts, which were reported to have occurred near a military barracks in the west coast oil producing nation, was not immediately apparent.

The country’s ministry of health and social welfare declared a health emergency and said many were missing under the rubble. Video captures scenes of people digging for victims, as thick smoke wafted over the debris-strewn landscape. Others fled through the streets, some with suitcases and children in hand underneath a darkened sky.

The ministry said that rescue workers were bringing the injured to at least three hospitals in the city. Officials appealed for blood donations. Pickup trucks were loaded with survivors, Reuters reported and driven the front of one hospital — where some victims could be seen lying on the floor.