Iran's northwestern region has suffered several attacks of late blamed on Kurdish armed groups [Gallo/Getty]

Iran's state news agency has said that 18 people were killed in an explosion on Tuesday at a Revolutionary Guards military base in the country's northwest.

Iran's Fars news agency reported quoting Yadollah Bouali, a military commander, that some of the casualties in Tuesday's blast were workers at the base, but he did not specify whether they included members of the Guards.

"In yesterday's explosion at one of the Guards' bases in Lorestan [in western Iran], 18 people were killed and 14 wounded," he said.

Bouali said that the explosion hit when fire spread to the munitions store at the base near the provincial capital, Khorramabad, some 500km southwest of the capital, Tehran.

Iran's remote northwestern border region has witnessed several attacks in recent months by ethnic Kurds angry with the central government.

Powerful force

Iran's Arabic-language Al-Alam television cited a military source as saying that "some soldiers" were among the dead at the Imam Ali base.

The Revolutionary Guards have emerged as a powerful military and economic force in Iran in recent years, especially under the presidency of Mahmoud Ahmadinejad.

The force was set up after the Islamic revolution of 1979 with the stated aim of defending the revolution against internal and external threats.

The Guards were heavily involved in the government's crackdown on opposition protests that erupted after last's year presidential election results which gave Ahmadinejad a second term.

The force and some of its industrial wings have been targeted by UN sanctions imposed on Iran for pursuing its controversial nuclear programme.