DAR ES SALAAM, A series of large blasts struck the main military munitions dump in Tanzania’s commercial capital on Wednesday night but the number of casualties was unclear, defence minister Hussein Mwinyi said on Thursday.

A chain of explosions lit up the night sky and sent thousands of Dar es Salaam residents into a panic, and forced authorities to shut the country's main airport to aircraft.

The blasts hit the Gongo la Mboto military base in Ilala district, a few kilometres from the Dar es Salaam International Airport.

“The explosions occurred at the main military arms depot in Dar es Salaam. The airport was closed last night as a precaution,” Mwinyi told Reuters by telephone.

“The explosions have now stopped ... I cannot confirm the extent of casualties yet.”

The cause of the explosions could not be immediately established, he said.

Roads leading to and from the Dar es Salaam airport were closed after the explosions on Wednesday night.

“The airport was closed after the explosion. The situation is now calm. There was no major damage to the airport’s infrastructure,” Mwajuma Kiponza, commander of the Dar es Salaam airport police unit, told Reuters.

Kiponza said that as of Thursday morning, the airport remained closed to air traffic.

Eyewitnesses and media said several people were killed from the blasts and dozens were rushed to hospital for emergency treatment.

The blasts scattered debris across densely populated neighbourhoods several kilometres away from the military base.

“I live some 15 kilometres from the military base, but my neighbour's house was struck by debris from a rocket propelled grenade. Luckily, no one was injured because we were told to evacuate our homes,” said Hassan Kondo, a resident of the Kivule area on the outskirts of Dar es Salaam.

“At least one person was killed from the explosion in our neighbourhood and several were injured.”

A similar explosion in 2009 at another military base in Dar es Salaam killed at least 26 people and wounded more than 700.