A massive explosion at a military arms depot near the Iranian capital Tehran killed 17 people on Saturday and wounded 15, in what officials were treating as an accident.

A spokesman for the Revolutionary Guards - Iran's elite military force - said the blast happened as troops were moving munitions at a base in Bidganeh, near the town of Shahriar.

Open gallery view Under a portrait of the late Iranian revolutionary founder Ayatollah Khomeini, Sam-6 missiles are displayed by Iran's Revolutionary Guard. Credit: AP

"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 state TV news channel IRINN.

"Some of the wounded are reported to be in a critical condition," he added. The semi-official Fars news agency said 25 people had been taken to hospital.

According to past reports by Iranian opposition groups, the village of Bidganeh is where the Fifth Raad Missile Brigade is stationed. The brigade is responsible for launching Shahab 3 and 4 missiles. Satellite images of the site reveal two large military bases near the village.

The blast was so big it was felt in western suburbs of Tehran, 45 km away, witnesses told Reuters. Many assumed there had been a low-level earthquake. Some media reports said the initial blast was followed by a second explosion.

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 United States, which have not ruled out striking nuclear facilities they believe are working towards making atomic weapons, a charge Tehran denies.

On Oct. 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.

In recent years several mysterious explosions took place in military installations in Iran. Two years ago 20 people were killed in a similar blast at a base 500 kilometers southwest of Tehran. According the Washington-based Global Security Institute, the base was used to assemble and store long-range Shihab-3 missiles.

Foreign media has reported in the past that Israel's Mossad intelligence service backs certain opposition activists and underground movements, and uses them to carry out attacks. Iran has blamed the CIA, Mossad and British intelligence in backing Jundollah (God's soldiers), a group which has waged a low-level insurgency in recent years. Its members accuse Iran's mostly Shi'ite government of persecution and have carried out attacks against the Revolutionary Guard and Shi'ite targets in southeastern Iran.

קראו כתבה זו בעברית: 15 הרוגים בפיצוץ רב עוצמה בבסיס של משמרות המהפכה באיראן