(AP) An ambulance with flashing lights on Monday left the site of a flooded cave in northern Thailand where a youth soccer team has been trapped for two weeks, just hours after the second phase of a rescue operation was launched.
 
The ambulance drove toward a helipad, where a helicopter was seen taking off shortly after to the cheers of the crowd below. The same process was used Sunday for at least one of the four boys rescued in the first attempt at getting the 12 boys and their coach out of the underground cave complex.
 
Less than an hour after the helicopter took off, Thai public television aired live video of a medivac helicopter landing close to a hospital in the city of Chiang Rai, around 60 kilometers (37 miles) from the cave. Medics appeared to remove one person on a stretcher but hid the person's identity behind multiple white umbrellas.
 
It was not clear who was inside the ambulance or the helicopter. Multiple calls to senior government officials and military personnel leading the rescue operation rang unanswered Monday evening. On Sunday, officials waited until several hours after the rescued boys had been transported to hospitals to announce their rescue.
 
Chiang Rai acting Gov. Narongsak Osatanakorn had said earlier Monday that the second phase began at 11 a.m. and authorities "hope to hear good news in the next few hours." Nine people remained trapped in the cave, including the team's coach, as of Monday morning.
 
"All conditions are still as good as they were yesterday," Narongsak told a news conference. "The boys' strength, the plan - today we are ready like before. And we will do it faster because we are afraid of the rain."
 
Authorities have been rushing to extract the boys, ages 11-16, and their coach from the cave as the annual monsoon bears down on the mountainous region in far northern Chiang Rai province. Workers have been laboring around the clock to pump water out of the cave, and authorities said Monday that heavy downpours overnight did not raise water levels inside.
 
The four boys pulled from the cave Sunday in an urgent and dangerous operation that involved them diving through the cave's dark, tight and twisting passages were happy and in good health, authorities said.
 
"This morning they said they were hungry and wanted to eat khao pad grapao," Narongsak said, referring to a Thai dish of meat fried with chili and basil and served over rice.
 
Still, the four were undergoing medical checks in a hospital in the provincial capital and were not yet allowed close contact with relatives due to fear of infections. Relatives were able to see them through a glass partition, the governor said.
 
The boys and their coach went exploring in the massive Tham Luang Nang Non cave on June 23 after a soccer practice, and were cut off when a rainstorm flooded the cave. A massive international search operation was launched and it took 10 days to locate the boys, who had taken shelter on a dry slope deep in the complex.
 
The search and rescue operation has riveted people both in Thailand and internationally, with journalists from across the globe traveling to this town along the border with Myanmar to report on the ordeal.
 
Interior Minister Anupong Paojinda had said early Monday that the same group of expert divers who took part in Sunday's rescue would return to extricate the others because they know the cave conditions and what to do. He had said fresh air tanks needed to be laid along the underwater route.
 
Authorities have said extracting the entire team from the cave could take up to four days, but Sunday's success raised hopes that it could be done faster.
 
Sunday's mission involved 13 foreign divers and five Thai navy SEALs. Two divers accompanied each of the boys, all of whom have been learning to dive only since July 2, when searchers found them.
 
Cave rescue experts have said they consider an underwater escape to be a last resort, especially with people untrained in diving.
 
The death Friday of a former Thai navy SEAL underscored the risks. The diver, the first fatality of the rescue effort, was working in a volunteer capacity and died on a mission to place air canisters along the passage to where the boys are, necessary for divers to safely travel the five- to six-hour route.
 
There were several concerns that prompted authorities to move forward with the plan to dive the boys out. One was that it was unknown how safe and dry the area where they had taken shelter would stay as Thailand's rainy season, which lasts until at least late October, picks up pace.
 
The other, and perhaps more worrying, was that oxygen levels in the complex were falling close to dangerous levels.