By Felix Tam and Twinnie Siu

HONG KONG (Reuters) – Hong Kong’s leader announced the closure of four more border crossings with mainland China on Monday, leaving just three checkpoints open, but stopped short of demands for the entire border to be closed to curb the spread of the new coronavirus.

Hong Kong has 15 confirmed cases of the coronavirus, which emerged in central China in December and has killed more than 360 people there and sent jitters through global markets.

Carrie Lam, chief executive of Chinese-ruled Hong Kong, was speaking hours after more than 2,500 workers from the Hospital Authority Employees Alliance (HAEA) went on strike to call for the border to be shut and better protection for hospital staff, among other demands.

“We should be united if we have the same goal. At this critical moment, (some people are) taking extreme means and it is inevitable it will affect the rights of patients,” Lam said.

“Those using extreme means to try to force the government’s hand will not succeed.”

The Hospital Authority said those using extreme means “to try to force the government and Hospital Authority’s hands will not succeed”.

Striking workers at the Hospital Authority building booed as they watched Lam speak, calling her a liar and chanting: “Close all borders.”

The medical workers, members of the newly formed union, held a press conference shortly after Lam spoke and said they planned to keep up their strike action.

HAEA chairwoman Winnie Yu said she expected around 9,000 of the alliance’s roughly 18,000 members to strike on Tuesday.

Pro-democracy protesters have in recent months formed about 40 unions as a way to press their demands on the government and at least a dozen have come out in support of the HAEA’s strike.

Reflecting concerns in the broader business community, three-quarters of American business leaders polled said they wanted Hong Kong to shut the border with the mainland, according to a survey of 156 executives by the American Chamber of Commerce in Hong Kong.

Lam has rejected calls to shut the entire border, saying such a move would be “inappropriate and impractical” as well as “discriminatory”.

By making it inconvenient for people to cross the border, Lam said she hoped it would help contain the spread of the virus although she does not “rule out future measures as the situation evolves”.

The health scare comes after months of at times violent anti-government protests in Hong Kong triggered by fears the city’s autonomy, guaranteed under a “one country, two systems” formula, is being eroded by Beijing.

China denies meddling and accuses foreign governments of fomenting the unrest.

The virus is expected to heap more pressure on the former British colony, which on Monday reported its economy contracted for the first time in a decade in 2019.

The HAEA’s five demands are for the government to close the border, distribute masks to the public, ensure that front-line medical workers have adequate supplies and protection, provide enough isolation wards for patients and guarantee no reprisals for strikers.

Panic-stricken residents have emptied shelves in major supermarkets in Hong Kong, stockpiling meat, rice and cleaning products as fears escalate over the coronavirus.

About 90 percent of the city’s food is imported, with the bulk coming from the mainland, according to official data.

Toy shop owner Lam Wa-yin, 45, said closing the border would intensify worries about supplies of staples.

“They’ve started rushing to buy supplies even before they fully close the borders,” Lam said.

“It’ll get worse if it is fully closed. Especially food. People have been rushing to buy oil, salt and rice, not to mention the face masks.”

(Reporting By Felix Tam, Joseph Campbell, Twinnie Siu, Jessie Pang, Yoyo Chow; Writing by Anne Marie Roantree; Editing by Robert Birsel)