Mark Zuckerberg says he is “deeply disappointed” that a Facebook satellite was destroyed by the explosion of a SpaceX rocket which was preparing to launching it into orbit.

The eruption occurred during preparations the Saturday of the unmanned rocket and its cargo on the weekend. Facebook intended to use the rocket to extend internet coverage across Africa.

NASA says SpaceX was conducting a test firing when the blast occurred on Thursday morning.

The payload was an Israeli Amos 6 satellite for Facebook, a $200 million dollar project which would have provided free broadband coverage over the sub–Sahara, where the infrastructure for easy internet access is lacking.

The test, considered routine, was in advance of a planned Saturday launch from Cape Canaveral Air Force Station.

There were no injuries.

The explosion apparently happened during a fuelling exercise, and was related to a problem with the launch pad, not the rocket.

Statement on this morning's anomaly pic.twitter.com/3Xm2bRMS7T

— SpaceX (@SpaceX) September 1, 2016

Buildings several miles away shook from the blast, and multiple explosions continued for several minutes. A cloud of dark smoke filled the overcast sky and hovered over Florida for hours.

SpaceX later tweeted an update on the cause.

Update on this morning's anomaly pic.twitter.com/1ogCMPCY44

— SpaceX (@SpaceX) September 1, 2016

Facebook’s Mark Zuckerberg has issued a statement saying he was “deeply disappointed” at the loss of the communications satellite.

-AP and agencies