KABUL (AFP) - A huge explosion that shook central Kabul on Thursday was an accident in an arms depot, officials said, allaying fears of an attack on the Afghan capital that has often been targeted by militants.

"It was an accident, not an enemy act," Lutfullah Mashal, a National Directorate of Security (NDS) official said.

"The blast happened in a depot for unexploded ordinance. It was totally an accident. There is no reported casualties but there are some damages."

The large explosion outside Nato's International Security Assistance Force headquarters rocked central Kabul on Thursday,
although there was no immediate confirmation of casualties.

The blast came the day after a Taliban suicide bomber detonated an explosives-laden vehicle near a Nato military convoy entering the city's airport, killing himself but causing no other deaths or injuries.