Multiple explosions continued for several minutes on Thursday where a SpaceX Falcon 9 rocket was scheduled to carry an Israeli communications satellite into orbit this weekend. Initial reports compared the sound of the first blast to lightning, saying it was followed by several more explosions.

SpaceX had been carrying out a routine test firing of the unmanned rocket when the blast occurred. The test came two days before a planned launch at the Cape Canaveral Air Force Station on Saturday.

"SpaceX can confirm that in preparation for today's standard pre-launch static fire test, there was an anomaly on the pad resulting in the loss of the vehicle and its payload. Per standard procedure, the pad was clear and there were no injuries," the California-based company, led by billionaire Elon Musk, said in a statement.

Photos quickly began circulating on social media showing a large plume of black smoke rising into the air.

One user who appeared to work miles away from the site of the blast said the explosion had shaken their entire building.

Local emergency responders wrote on Twitter that the explosion was a contained incident that posed no danger to people who live and work in the area. Personnel at NASA were monitoring the air for any toxic fumes.

The blast occurred shortly after 9 a.m. local time. At 8:29 a.m., the space exploration agency tweeted a video of two astronauts on a spacewalk at the International Space Station.

The astronauts were reportedly not immediately informed about the explosion back on Earth.

cjc/sri (AP, dpa, Reuters)