SEOUL--Churches were closed in South Korea on Sunday with many holding online services instead, as authorities fought to rein in public gatherings, with 376 new coronavirus infections taking the tally to 3,526 cases.

That came a day after the biggest daily jump of 813 cases in South Korea's battle with the largest virus outbreak outside China, said the Korea Centers for Disease Control and Prevention (KCDC), which will update numbers later in the day.

The death toll of 17 was unchanged from Saturday, it added.

In Seoul, the capital, about a dozen worshippers were turned away from the Yoido Full Gospel Church, which put a sermon for its 560,000 followers on YouTube, filmed with a small choir instead of all 200 members and 60-strong orchestra.

"I had heard there would be no service, but just came to check as I live nearby, but yes, it is so empty," said one of them, Song Young-koo, as he left South Korea's biggest church.

"It's a wise decision to do it online, since the virus would easily spread at mass gatherings and churches can be no exception."

Of the new cases, 333 were from the southeastern city of Daegu, the location of a church at the centre of the outbreak, and 26 from the nearby province of North Gyeongsang, KCDC said.

Health authorities have urged South Koreans to refrain from attending religious services and political events and stay indoors this weekend, warning of a "critical moment" in the battle on the virus.

For the first time in its 236-year history, South Korea's Catholic church decided to halt masses at more than 1,700 locations nationwide. Buddhist temples have also called off events, while major Christian churches held online services.

At Yongsan in central Seoul, a notice outside the large Samil Presbyterian Church advised parishioners all gatherings had been cancelled, with the parking area closed off.

HELP FOR NORTH KOREA

President Moon Jae-in called for unity and vowed greater efforts, including an extra budget, to fight the outbreak, in a speech for the 101st anniversary of a movement to win independence from Japanese colonial rule.

"The outbreak can threaten our lives temporarily, but it cannot break our unity and hope," Moon said in the speech.

Moon proposed joint efforts with North Korea to prevent an outbreak in the neighbor and improve healthcare.

North Korea has not confirmed any cases but imposed a month-long quarantine for those with symptoms, and state media said its leader, Kim Jong Un, held a meeting on stricter measures.

The crisis spooked trade and financial markets, leading Samsung Electronics, Hyundai Motor and LG Display to temporarily shut down a plant each and prompting boy band BTS to cancel a world tour set for April.

More neighbors suspended flights and banned visitors from South Korea.

In a statement, Seoul's foreign ministry said Foreign Minister Kang Kyung-wha asked Washington to avoid "excessive action that could needlessly shrink exchanges between both countries," in a telephone call on Sunday with U.S. Deputy Secretary of State Stephen Biegun.

The request came after the United States advised Americans not to travel to hard-hit regions, such as Daegu.