Police have been guarding the Seoul Central Mosque since anonymous callers threatened to blow up the blue-tiled, twin-minareted house of prayer earlier this week.
"I think a lot of people won't come out today because of the harassment," said Shariq Said, an official of the Korea Muslim Federation headquartered in the hilltop mosque compound. "But the security is very good."
Noticeably absent from Friday prayers were some of the country's newest followers - a handful of South Korean soldiers who converted ahead of their dispatch to Iraq.
Last week - before the nation was shocked by televised images of a bedraggled Kim Sun-il pleading for his life - the troops turned out as they had done for weeks, shedding their boots at the mosque's doorstep to pray in camouflaged fatigues emblazoned with South Korean flag patches.
The Defence Ministry said the Muslim soldiers didn't turn up on Friday because they were attending training.
Kim Sun-il was executed by his
captors after a deadline passed
But their absence underlines growing sensitivity over Seoul's plan to send 3000 more troops to Iraq, making it the biggest occupation partner after the United States and Britain.
Iraqi fighters beheaded Kim on Tuesday after the South Korean Government refused to bow to their demands and stop the dispatch. South Koreans were outraged by video footage of the blindfolded Kim kneeling in an orange jumpsuit in front of his masked captors who later sliced off his head with a sword.
Most channelled their anger at the killers while others blamed the government for refusing to change its plans.
Subject of interest
South Korea's 180,000-strong Muslim community, all but forgotten in this predominantly Buddhist and Christian nation of 47 million, has suddenly become the subject of interest, curiosity - and ire.
In one incident, an angry man stormed into the Central Mosque compound ranting anti-Muslim slogans. But on Friday, Korean Muslim Federation President Abd al-Raziq said: "There's no problem now."
"Most Koreans don't understand Islam. People always say I'm the first Korean Muslim they've ever met. They think it's pretty special"
Moon Sung-jo, a university student
Worshippers at Central Mosque said they shared the rest of the country's anger at Kim's death, but cautioned that the killers, not their faith, should shoulder the blame.
"Such terror acts are against our law," said Moon Sung-jo, 25, a university student who is among the sliver of 30,000 ethnic Koreans in a Muslim population dominated by foreigners.
"Most Koreans don't understand Islam. People always say I'm the first Korean Muslim they've ever met. They think it's pretty special."
Islam was unknown to most Koreans until the 1900s. Among the first Koreans to join the faith were World War II conscripts in the Japanese military who converted while serving in China.
Turkish troops who fought with United Nations forces in the 1950-53 Korean War had no place to worship, and the Seoul Central Mosque wasn't built until 1976.
The Defence Ministry tried to counter this lack of familiarity by teaching its Iraq-bound troops about the ways of Islam. The 3000 soldiers that will begin deploying in northern Iraq in August will join about 600 military medics and engineers already operating in the country's south.
Three thousand soldiers will be
dispatched to Iraq in August
"We thought learning about Islamic culture and religion would help our mission in Iraq," a Defence Ministry spokesman said on condition of anonymity.
Soldiers with no religious background were selected for three-week intensive education in Islam so they could help smooth relations between South Korean forces and Iraqi government and religious leaders.