UPDATE | No injuries at explosion at SpaceX launch pad; rocket, satellite destroyed

CAPE CANAVERAL, Fla. (AP) — A massive explosion erupted today at SpaceX's main launch pad, destroying a rocket as well as a satellite that Facebook was counting on to spread internet service in Africa.

There were no injuries. The pad had been cleared of workers before what was supposed to be a routine rocket test.

The mishap dealt a severe blow to SpaceX, still scrambling to catch up with satellite deliveries after a launch accident last year. It's also a setback for NASA, which has been counting on the private company to keep the International Space Station stocked with supplies and, ultimately, astronauts.

SpaceX was working to conduct a test firing of its unmanned Falcon rocket when the blast occurred shortly after 9 a.m. at Cape Canaveral Air Force Station. The test was in advance of Saturday's planned launch of an Israeli-made communications satellite that was supposed to provide home internet for parts of sub-Saharan Africa and the Middle East.

SpaceX said that in preparation for today's engine firing – a test carried out a few days before every launch – "there was an anomaly on the pad resulting in the loss of the vehicle and its payload." No additional details were provided. It wasn't clear whether the rocket caused the problem or something else on the pad.

It's the same kind of SpaceX rocket used to launch space station supplies for NASA.

Buildings several miles away shook from the blast, and multiple explosions continued for several minutes – one right after another. Dark smoke filled the overcast sky. A half-hour later, a black cloud hung low across the eastern horizon.