Twenty seven Iranian servicemen were killed and several others seriously wounded in an explosion on Saturday at a military base near Tehran that happened as troops were moving munitions, a Revolutionary Guards spokesman told state TV.

'My dear colleagues in the Revolutionary Guards were moving munitions in one of the arsenals at that base when, due to an incident, an explosion happened,' Ramezan Sharif told news channel IRINN.

'Some of the casualties are reported to be in a critical condition,' he added.

Residents in western suburbs of Tehran, 45 km away, told Reuters they had felt the blast, assuming it to be a low-level earthquake. Some media reports said the initial blast was followed by a second explosion.

The explosion happened around noon (0930 GMT) and the fire was still raging at the Amir Al-Momenin military base more than four hours later, the semi-official Fars news agency said.

Media were being kept away from the scene and no television pictures were immediately available.

There were no reports linking the blast to any air strike or other attack. Tension has risen in recent weeks between Iran and its enemies Israel and the US, which have not ruled out striking facilities they believe are working towards making nuclear weapons, a charge Tehran denies.

On October 12 last year a similar blast at a Revolutionary Guards munitions store killed and wounded several servicemen in Khoramabad, western Iran. Authorities said that explosion was an accident.-Reuters