TEHRAN, Iran >> Millions of Shiite Muslims in Iran, Afghanistan, Pakistan and around the world on Friday commemorated Ashoura, a remembrance of the 7th-century martyrdom of the Prophet Muhammad’s grandson, Hussein, that gave birth to their faith.

In Afghanistan, the Taliban cut mobile phone services in key cities holding commemorations for fear of militants targeting Shiites, whom Sunni extremists consider heretics. Security forces in neighboring Pakistan as well stood on high alert as the commemorations there have seen attacks in the past.

Not all Shiites, however, were to mark the day Friday. Iraq, Lebanon and Syria planned their remembrances for Saturday, which will see a major suburb of Beirut shut down and the faithful descend on the Iraqi city of Karbala, where Hussein is entombed in a gold-domed shrine.

Shiites represent over 10% of the world’s 1.8 billion Muslims and view Hussein as the rightful successor to the Prophet Muhammad. Hussein’s death in battle at the hands of Sunnis at Karbala, south of Baghdad, ingrained a deep rift in Islam and continues to this day to play a key role in shaping Shiite identity.

Over 1,340 years after Hussein’s martyrdom, Baghdad, Tehran, Islamabad and other major capitals in the Middle East were adorned with symbols of Shiite piety and repentance: red flags for Hussein’s blood, symbolic black funeral tents and black dress for mourning, processions of men and boys expressing fervor in the ritual of chest-beating and self-flagellation with chains.

In Iran, where the theocratic government views itself as the protector of Shiites worldwide, the story of Hussein’s martyrdom takes on political connotations amid its tensions with the West over its advancing nuclear program.

Iranian state television aired images of commemorations across the Islamic Republic, tying the event to criticizing the West, Israel and the U.S. drone strike that killed Iranian Gen. Qassem Soleimani in 2020. Anchor Wesam Bahrani on Iran’s state-run English-language broadcaster Press TV referred to America as the “biggest opponent of Islam” and criticized Muslim countries allied with the U.S.

Men wore black, rhythmically beating their chests in mourning or using flails to strike their backs. Some wore red headbands, as black and red banners bore Hussein’s name. Some sprayed water over the mourners in the intense heat.

“Every year everyone joins hands in solidarity,” said 23-year-old Mohammad Hajatmand, who took part in a processional in Tehran. Hussein “was martyred very brutally and when anyone hears the story of Ashoura, regardless of their religion, their hearts will be broken and they will sympathize with him.”

The commemoration in Iran also comes as Tehran prepares for the one-year anniversary of the death of Mahsa Amini. Her death launched protests nationwide in Iran that reportedly saw more than 500 protesters killed and some 20,000 others detained. Authorities have begun stepping up their enforcement of mandatory hijab, or headscarf, laws for women in recent weeks.

In the suburb of Sayida Zeinab near Syria’s capital, Damascus, security forces guarded checkpoints after a bomb hidden in a motorcycle exploded Thursday, killing at least six people and wounding dozens more. On Tuesday, another bomb in a motorcycle wounded two people. The suburb is home to a shrine to Zeinab, the daughter of the first Shiite imam, Ali, and granddaughter of the Prophet Muhammad.

Local resident Mustafa Semaan, 41, said the area had seen a resurgence of religious tourism after security stabilized amid Syria’s ongoing war and the worst of the coronavirus pandemic.

“I don’t believe the religious observances will be affected (by the recent bombings), but the economic situation as a result of visitors coming from outside Syria may be affected,” Semaan said. “If this continues, if there were a third attack, there might be a very negative impact.”

On Friday, the Islamic State claimed responsibility for the recent attacks in a statement, claiming that Thursday’s attack killed about 10 and wounded about 40 others “during their annual polytheistic rituals.” The group’s extreme interpretation of Islam holds Shiite Muslims to be apostates.

In 2014, IS overran large swaths of Syria and Iraq and declared the entire territory a “caliphate,” where it imposed a radically brutal rule. The U.S. and its allies in Syria and Iraq, as well as Syria’s Russian-backed government troops, fought against it for years, eventually rolling it back. However, the extremist group’s cells have continued to carry out attacks.

Iraq will see the main observance of the Ashoura on Saturday in Karbala, where hundreds of thousands are expected and many will rush toward the shrine to symbolize their desire to answer Hussein’s last cries for help in battle. Convoys of the faithful arrived throughout the day Friday.

Meanwhile, hundreds of Iraqi Shiites in Baghdad’s Sadr City participated in Ashoura rituals, including slashing their heads with swords and self-flagellation in a show of grief.

Those marking the commemoration in Kabul, Afghanistan, beat their backs bloody with chains and knives in ritual bloodletting known as “tatbir,” meant to recreate the blood flowing from the slain Hussein. The practice has become debated among Shiite clerics in recent decades.

“We have only one problem that (the Taliban) are preventing us to raise our flags and enter (the city) with the flags,” said Karbalayee Rashid, an organizer of the Kabul commemoration. “Thank God the security has been taken care. It is OK, but there are more limits in this country this year than last year.”

In Pakistan, authorities stepped up security as an Interior Ministry alert warned that “terrorists” could target Ashoura processions in major cities. Security was tight in the capital, Islamabad, where police were deployed at a key Shiite place of worship.

The main Ashoura processions also got underway in the eastern city of Lahore in the Punjab province, where thousands of police officers have been deployed. Processions in Karachi and elsewhere were also starting. There was no immediate report of any violence.

“The Imam’s lesson is … hold on to patience,” said Anam Batool, a mourner who took part in a commemoration in Islamabad. “After that, resist falsehood, stand with the truth. Where you must raise your voice against oppression, raise your voice there.”

Associated Press writers Abby Sewell in Baghdad; Anmar Khalil in Karbala, Iraq; Munir Ahmed in Islamabad; and Jon Gambrell in Dubai, United Arab Emirates, contributed to this report.