SEOUL, SOUTH KOREA - South Korea confirmed its first death from the new coronavirus, local media reported Thursday, as the number of infections in the country tripled within two days.

The Korea Center for Disease Control and Prevention said in a statement the exact cause of death is being investigated. The report came as the country grapples with the outbreak and its economic impact.

South Korea reported 53 new coronavirus infections Thursday, bringing the total number of cases in the country to 104.

South Korean authorities have warned the outbreak is entering a "new phase" and is now spreading locally, even among people who have no links to China, where the virus originated.

The virus, which causes a pneumonialike illness recently named COVID-19, has killed more than 2,100 people and infected more than 75,000 worldwide. Almost all the infections have been in China.

Spreading locally

Almost all of the latest South Korean coronavirus infections were in Daegu, the country's fourth-largest city.

Many were linked to a religious group called the Shincheonji Church of Jesus the Temple of the Tabernacle of the Testimony, which was founded in 1984 by Lee Man-hee, who is revered by his followers as a messiah.

Daegu's mayor has cautioned residents to stay inside their homes to prevent a further outbreak.

There are fears that the new coronavirus "has spread deep within Korea undetected," said an editorial in the Chosun Ilbo, a major South Korean newspaper.

"Existing measures to deal with the outbreak are not working," it continued.

Economic damage

The outbreak could have a major impact on South Korea's economy, which was already experiencing lagging growth. Citing the virus scare, Moody's Investor Service Monday cut its forecast for South Korea's economic growth in 2020 to 1.9% from 2.1%.

Moody's also said China is now expected to experience 5.2% growth in 2020, down from an earlier estimate of 5.8%.

Economic turmoil in China is acutely felt in South Korea, because Beijing is Seoul's top trading partner. Some South Korean automakers, including Hyundai and Kia, temporarily halted or reduced production because of a shortage of parts from China, where many factories have closed.

South Korean President Moon Jae-in said Tuesday that the situation is "more serious than we thought," adding that "emergency steps" are needed to contain the economic fallout.

US military on alert

The U.S. military, which has more than 28,000 troops in South Korea, has implemented precautionary measures to prevent the spread of the virus.

The latest outbreak in Daegu, about a three-hour drive south of Seoul, is especially worrying as the United States has thousands of troops in the area.

All nonessential travel to and from Daegu has been banned, and travel outside U.S. bases has been minimized, according to General Robert Abrams, the commander of U.S. Forces Korea.

The U.S. military has also implemented a "mandatory self-quarantine" for any service members who visited the Daegu religious group, where many of the latest infections were reported.