Surge testing for COVID-19 continued on the H-3 freeway on Thursday with more than 5,000 signing up in advance and vehicles lining up for miles on both sides of the Koolau mountains.

Officials held the free testing event for the second time this week and again defied the Federal Highway Administration, which denied permission to shut down the interstate that links windward Oahu and Honolulu.

The federal agency expressed numerous concerns about the shutdown in a letter that arrived at state offices Tuesday morning after the freeway already had been closed. The concerns included impacts to safety, traffic and the operations of Marine Corps Base Hawaii in Kaneohe.

Ed Sniffen, state Highways Division deputy director, said on Thursday that he responded to the agency with additional information describing how safe Tuesday’s event was and how it had little effect on traffic elsewhere.

PHOTOS: COVID-19 surge testing returns to H-3 freeway

The Likelike and Pali highways operated without any delays, he said, and state officials coordinated with the Marines to accommodate all of its caravans.

“Operationally, it didn’t affect anything outside this facility,” Sniffen told the media outside the H-3 tunnel, the hub of the freeway testing.

The Federal Highway Administration couldn’t be reached for comment Thursday, but a spokesman on Tuesday said the agency was hoping to work with the state on alternatives to closing the freeway.

In its letter, the federal agency warned that the state could face the loss of funding or projects if it went ahead with the closure. Hawaii receives $180 million in federal highway funds annually.

As for Thursday’s testing, more than 5,000 pre-registered for the federally funded surge event, which ran from 9 a.m. to 2 p.m. but stayed open to accommodate those still in line. Thursday’s total represents a sizable jump from Tuesday’s 1,700 pre-registration total.

Thursday’s attendance boost was seen in the number of cars waiting in line. In the late morning, hundreds of vehicles were bumper to bumper on both sides of the tunnels, with queues snaking for about 3 miles on the windward side, and 2 miles on the Honolulu side. By the afternoon, wait times exceeded 2-1/2 hours.

Also on Thursday, the state Department of Health reported four new coronavirus-related deaths on Oahu and 211 new COVID-19 cases, bringing the statewide totals since the beginning of the pandemic to 79 fatalities and 9,202 cases.

Officials counted 6,291 new tests in Thursday’s tally, with a positivity rate of 3.4%.

In surge testing, the results have now come in for 10,316 individuals, with only 70 tested positive, according to the department.

The four fatalities all had underlying health conditions, officials said, including a man and a woman older than 80, plus a man in his 60s and a woman in her 70s. No other details were provided.

Meanwhile, an additional death was reported at the Yukio Okutsu State Veterans Home, the fifth one this week.

State health officials said they did not include the two latest fatalities at the Hilo veterans home in Thursday’s COVID-19 tally due to a pending verification process.

A total of 46 residents and 15 employees have now tested positive for COVID-19, according to Hilo Medical Center.

In response to growing numbers on Hawaii island, Mayor Harry Kim announced the opening of a central command post under his office that aims to coordinate county, state and federal coronavirus programs, as well as those offered by the private sector.

Aunty Sally Kaleohano’s Luau Hale in Hilo is being converted into an emergency operation center that will oversee everything from contact tracing to enforcement.

“We will all be working as a team on the same goal: to mitigate the spread of COVID-19 in our community and to keep our people safe,” Kim said in a statement.

State officials also announced Thursday that the Narnia area of streams and waterfalls above the J7 Ranch near Hilo will be closed to the public to prevent people from gathering during the pandemic.

The action comes after an estimated 100 people gathered at the J7 ranch last weekend to visit the streams and waterfalls, officials said.

On Oahu, special agents with the state Attorney General’s Office paid two Waikiki hotels a surprise visit Thursday to check on nearly two dozen people under COVID-19 travel quarantine orders.

“We had 100% compliance,” said Paul Jones, deputy chief special agent with the AG’s Investigations Division.

Gov. David Ige’s quarantine order requires all travelers, visitors or returning residents to self-quarantine for 14 days unless granted an exemption.

Jones said agents on Thursday made contact with everyone on a quarantine list of travelers provided by the Hawaii Tourism Authority.

Over the past few months, special agents, working with the Honolulu Police Department, have arrested more than 30 people on Oahu for violating quarantine. These individuals were either posting their activities on social media or had been reported to authorities by witnesses.

Those arrested for violating quarantine face fines up to $5,000 and jail time.