As the number of confirmed coronavirus cases in Hawaii jumped to 37 Friday, health officials sounded the alarm that community transmission of COVID-19 is occurring in the state’s largest and densest population center.

Eleven new cases were confirmed — one of them in a child, underscoring the fact that anyone can be affected, health officials said.

The disease was also confirmed in two people on Oahu who had no travel history or known exposure to tourists — the first sign of at least localized community spread.

“This is the first time we’ve seen any evidence of community transmission, with no history of exposure to someone who’s traveled,” state Health Director Bruce Anderson said during a conference call. “The disease is being transmitted in our community. This is the time to take everything that we said very seriously. We need to maintain social distancing, hand washing, avoiding large crowds. It’s not that it might happen, it is happening now.”

The statewide total for confirmed infections jumped from 26 on Thursday to 37.

“Quite frankly, I’m not surprised because of the fact that our population is so dense here (on Oahu). This is the highest-risk area,” said state Epidemiologist Sarah Park. “The closer people are together, the higher the risk.”

Authorities are considering stricter measures to enforce social distancing, and to restrict travel to Hawaii by imposing a 14-day quarantine for all returning visitors and residents, Anderson said.

The plan for Hawaii airports will involve hiring or reassigning roughly 500 people and cost about $1 million per month, according to the state Senate’s special committee on COVID-19.

But pressure was mounting on Gov. David Ige to take stronger steps to isolate the state from outsiders as California, New York and Illinois took sweeping measures aimed at keeping tens of millions of residents inside their homes amid the coronavirus outbreak.

A convoy of roughly 75 to 100 honking vehicles, flying Hawaiian flags, traveled in protest Friday afternoon from Daniel K. Inouye International Airport to Waikiki in protest of visitors being allowed to remain.

>> PHOTOS: Protesters rally against coronavirus threat that tourism brings to Hawaii

Organizer Kawena Phillips said plans to quarantine incoming travelers are a great place to start, but the group wants to see faster and more drastic actions taken by the state, such as urging visitors to return home and encouraging hotels to shut down. He cited the lack of enough ICU beds for residents, and said sick tourists could further tax the health care system.

One protester using a bullhorn from the back of a pickup truck in Waikiki said, “Hawaii is not your quarantine. Please return to your homes immediately!”

All nine members of the Honolulu City Council signed a letter urging Ige to require that all visitors self-quarantine; order the Hawaii Tourism Authority and travel industry to halt all advertising campaigns marketing the state as a visitor destination; and deny entry to all cruise ships entering the state.

“It is our belief, with prudent and swift action, our isolation can be our asset in our efforts to protect the public health, safety and welfare of our residents,” Council Chairman Ikaika Anderson said in a news release. “We recognize these actions will have immediate and significant economic impacts, but we have grave concerns that a prolonged and widespread outbreak in our state will hurt our city for years.”

Mayor Kirk Caldwell said he supports the Council’s letter.

While community spread has begun, there was a bit of relief when health officials found no positive cases of the new coronavirus in 185 randomly selected negative flu samples.

COVID-19 testing has improved in recent days as more private labs are established. However, personal protective equipment and other medical supplies are in short supply, so people who are not showing symptoms should not seek to be tested, Anderson said.

Personal protective equipment that health providers use to avoid contracting infectious diseases, ventilators for those with serious respiratory illness and other medical supplies are “going to be desperately needed in the months to come,” he said.

“We assume the problem is going to get a lot worse before it gets better,” said Anderson. Health officials are worried because some hospitals are estimating they could be out of certain supplies as early as the next couple of weeks or month.

How bad the situation gets in Hawaii is highly dependent on how well people follow social distancing orders.

“We need strong actions to prevent person-to-person spread. A lot is going to depend on how serious people take the situation. This is not a two- or three-week situation. We’re talking about months,” Anderson said. “A lockdown would imply temporary … then we can let everyone out of the shelters, if you will. That is not a scenario we think is likely here. We’re talking about several months, probably longer, before we see a situation where there is a decrease and where we can relax on some of our controls.”

Not everyone is heeding the government warnings. Beaches and hiking trails were full this week with people enjoying the outdoors but not maintaining a distance of 6 feet apart to avoid contracting the virus.

“If people continue to go to the beach as they have been, we have no choice but to impose more stringent, Draconian measures,” he said. “If we can’t control gatherings and restaurants don’t close, then we have no choice but to go down that road.”

For questions or more information, call 211 or go to hawaiicovid19.com.