A bomb exploded at a military parade in northwestern Iran on Wednesday, killing 10 spectators in an attack that one official blamed on Kurdish separatists who have fought Iranian forces for decades.

The blast in the city of Mahabad, close to the borders with Iraq and Turkey, also injured 57 people, Iranian media reports said. Most of the victims were women and children, said provincial Governor Vahid Jalalzadeh, who was quoted in a report by Iran's state broadcasting company.

Iranian forces in the border zone have for years clashed with Kurdish rebels from the Iranian wing of the Kurdistan Workers Party, which also has fighters based in Turkey and Iraq. The group in Iran has generally not targeted civilians in its campaign for greater rights for the Kurdish minority, raising the prospect that the bomb might have gone off prematurely.

A state radio report said the device was detonated on a timer and had been placed under a bush near the parade route.

Jalalzadeh said that explosion was carried out by "counterrevolutionaries," a reference to the Kurdish separatist group. He called the bombing "a terrorist incident."

The parade was one of several events around the country to mark the 30th anniversary of the start of the Iran-Iraq war. No military personnel were wounded, Jalalzadeh said.

The Mehr news agency said the dead included the wives of two of ranking military officers.

"The explosion happened opposite the VIP stage among women who were present there," Jalalzadeh was quoted as saying in the state TV report.

The Iranian branch of the Kurdish rebel group, the Party for Free Life in Kurdistan, says it is fighting for greater rights in Iran.

The city of Mahabad is home to 190,000 people _ most of them Kurds and Sunni Muslims. Iran is predominantly Shiite.

Mahabad was once the capital of the self-proclaimed republic of Kurdistan in Iran. Iran's armed forces recaptured Mahabad in 1946.