DUBAI, United Arab Emirates (AP) _ At least eight soldiers were killed and about a dozen injured by a huge explosion in an ammunition dump in northeastern Iran on Tuesday, an exile Iranian opposition group said.

The Iraqi-based Mujahedeen Khalq said the ammunition dump near the city of Mashhad was deliberately set on fire, causing explosions that continued for several hours.

Mujahedeen spokesman Ali Safavi said the attack about 500 miles east of Tehran was deliberate but that his group was neither claiming nor denying responsibility for it. The Mujahedeen have staged several mortar attacks on Iranian cities during the past year, the last as recently as Sunday in Tehran.

There was no immediate word from the Iranian authorities on an explosion.