A bombing at a martial parade in western Iran on Wednesday killed at least 12 people, including a 5-year-old and the wives of two Iranian military commanders. The explosion struck amid a large crowd attending the event, which was intended to underscore the nation’s battle readiness.

An additional 75 people were injured, at least 12 seriously, in what officials described as a “terrorist attack.” No one immediately claimed responsibility for the bombing, which occurred in the restive ethnic Kurdish city of Mahabad about 40 miles east of the border with Iraq.

Iranian officials quickly pointed to the United States, and the local Friday prayer leader blamed “Zionists.”

“As the investigations indicate, the attack has foreign backing,” Gov. Vahid Jalalzadeh of West Azerbaijan province, where Mahabad is located, told state television. “Unfortunately, the Americans and their allies are in the region. From the first day of their presence and their slogan to establish security in the region, we can see that the unrest has increased.”

U.S. Secretary of State Hillary Rodham Clinton in turn condemned the bombing.

“The perpetrators of this attack should be brought to justice and held accountable,” she said in a statement. “The United States condemns terrorism and all forms of violence against innocent people, wherever it occurs, and stands with the victims of these crimes.”

According to Iranian media, the bomb struck pedestrians gathered along a sidewalk to watch an annual Sacred Defense Week military parade commemorating the victims of the 1980-88 Iran- Iraq war. Initial news accounts described the attack as a suicide bombing. But state radio later reported that the bomb was placed in the branches of a pine tree.

The semiofficial Mehr news agency said that the 11 a.m. explosion took place 55 yards from the podium where military brass were watching the proceedings and that two of those killed were the wives of senior military commanders.

Mahabad lies in Iran’s restless Kurdish heartland and carries enormous symbolic weight for ethnic Kurds throughout the world. It was the capital of a short-lived Kurdish autonomous republic set up in 1946 and the birthplace of Massoud Barzani, the de facto leader of Iraq’s semiautonomous Kurdistan region.

The Kurdish separatist Free Life Party of Kurdistan operates in the area and has clashed with Iranian troops in recent years. The group condemned the blast and said it was not connected to it.

Iran has often accused the U.S. of supporting the rebel group, the Iranian branch of the Kurdistan Workers Party, which has been fighting the Turkish government for decades.

Kurds are believed to be the world’s largest ethnic group without a homeland. They have been fighting for autonomy and cultural rights against the governments of Iran, Iraq, Turkey and Syria for decades.

But a nearby mountainous stretch along the Iran-Iraq border also has sheltered Al Qaeda-linked Sunni Muslim extremist groups, such as Ansar al Islam.

daragahi@latimes.com