Professional sport returned to South Korea today as coronavirus restrictions eased there, with the first pitch thrown in a baseball preseason derby in front of empty stands.

The Seoul-based Doosan Bears and LG Twins are Korea's biggest rivals in the country's most popular spectator sport and their shared stadium in the capital's Jamsil area would usually be packed.

But the stands were empty with fans barred as the Twins' Cha Woo-chan threw the first pitch and cheerleaders were absent.

The stadium was silent except for the continuous clicking of camera shutters from around 50 members of the media and occasional shouts from the dug-outs. Reporters were not allowed to approach the players.

South Korea endured one of the worst early outbreaks of the disease outside China, prompting professional sports including football and baseball to suspend or delay their seasons.

Sports fans around the world have been starved of live action because of the virus, with broadcasters resorting to repeats of matches from past years, while leagues face the prospect of paying rights-holders multi-million-dollar refunds.

But South Korea appears to have brought its outbreak under control thanks to an extensive 'trace, test and treat' programme, and Seoul said at the weekend it would permit outdoor sport to resume behind closed doors in light of a steady decline in new virus cases.

The encounter was among the first of 20 preseason games, and the Korea Baseball Organisation said Tuesday the regular season would start behind closed doors on 5 May.

Strict health guidelines were being enforced. 

Players must have their temperature checked twice before the games, with facemasks strongly recommended in all parts of the stadium, except for the field and the dugout during the game, the KBO said.

Players have been asked not to shake hands or exchange high-fives while spitting is prohibited.

South Korea reported nine new COVID-19 cases on Monday - the country's fourth consecutive day of fewer than 20 new infections - taking the total to 10,683.

South Korean football clubs are also expected to be back in action soon after the K-League said they would be allowed practice matches from Tuesday.

The country's women golfers are also preparing to return to action, with the announcement that the four-day Korea Ladies Professional Golf Association (KLPGA) Championship would begin on 14 May in Yangju, east of Seoul.