TEHRAN, (AFP) – A suicide bomber blew himself up at a mosque in the Iranian city of Chabahar on Wednesday, killing at least 38 people and wounding 50 as Shiites marked the climax of Ashura, officials said.

According to the latest casualty toll, 38 people were killed and 50 wounded by the blast which struck near Farmandari Square among worshippers who were taking part in a procession,” the official, Mahmoud Mozafar, told the ILNA news agency.

“An individual walked up to some Red Crescent ambulances and blew himself up,” Mozafar added.

A pathologist cited by the official IRNA news agency said 38 bodies had been brought to the town’s mortuary, among them women and children.

The prefect of Chabahar Ali Bateni denied earlier reports that there had been two explosions and said there had been two, not three, attackers.

“There were two terrorists who were spotted before they carried out their attack but one of them managed to detonate his explosive vest,” he told IRNA.

“The ringleader of this terrorist action has been arrested.”

State media said that the bomber struck in the main square outside the Imam Hossein mosque in the southeastern city.

The attack came on the eve of the final day of Ashura, one of the high points of the Shiite calendar when large crowds of worshippers gather in mosques across Iran.

Unlike most of Iran, Sistan-Baluchestan province where Chabahar is situated has a significant Sunni community and has seen persistent unrest in recent years by the Sunni militant group Jundallah (Soldiers of God).

There was no immediate claim of responsibility for Wednesday’s bombing but over the past decade, Jundallah has claimed many deadly attacks on Iranian security forces as well as assaults that have led to civilian deaths.

In July, it claimed responsibility for an attack on the Grand Mosque in the provincial capital Zahedan that targeted members of Iran’s elite Revolutionary Guards Corps and killed 28 people.

Last month, the United States officially designated Jundallah a foreign terrorist organisation, drawing a cautious welcome from Iran which had previously accused Washington of supporting the group.

The authorities have cracked down hard on the group, arresting many suspected members and executing its leader Abdolmalek Rigi in June.

Rigi was captured in a dramatic operation in February while on a flight from Dubai to Kyrgyzstan, when Iranian warplanes forced the aircraft he was on to land in Iran.

A month before his execution, his brother Abdolhamid was also executed on charges of “terrorism.”

The 10-day Ashura rituals, which climax in Iran on Thursday, commemorate the killing of Imam Hussein, a grandson of the Prophet Mohammed, by armies of the caliph Yazid in 680 AD. Tradition holds that the revered imam was decapitated and his body mutilated.

Shiites make up around 15 percent of Muslims worldwide. They represent the majority populations in Iraq, Iran and Bahrain and form significant communities in Afghanistan, Lebanon, Pakistan and Saudi Arabia.