Updated at 7:52 a.m. ET

An elite team of Thai Navy SEALs and foreign rescue divers brought out the final four boys and their soccer coach from a cave near the Thai-Myanmar border, extracting the soccer team through a labyrinth of tight passages after they spent two weeks trapped in darkness.

The operation on Tuesday moved quickly, raising hopes that all 12 boys and their adult coach from the Wild Boars soccer team would be on the surface by the end of the day.

"Today, the boar's pack will be reunited again," the Thai navy SEALs, which is helping to lead the operation, said on its Facebook page.

Speaking earlier, acting Chiang Rai Gov. Narongsak Osatanakorn, who is also head of the joint command center, said, "If everything goes right, we will see four kids and a doctor and three Seals that have stayed with the kids will all come out."

Eight boys were taken out in the past two days — four on Sunday and another four on Monday. Three Thai Navy SEALs who were helping with the rescue must also be removed from the cave.

Operations to pump water out of the cave have continued, trying to combat heavy rains on Sunday and Monday. But rescue officials are also worried about dwindling oxygen levels in the cave.

Narongsak said 18 divers and a support team of 100 took nine hours in the second phase of rescues at the Tham Luang cave on Monday, as opposed to 11 hours on Sunday.

"We have more expertise than yesterday," he said.

The boys rescued so far are in good overall health despite spending two weeks in the dank cave system, Jesada Chokedamrongsuk, permanent secretary of the ministry of public health, told a news conference in Chiang Rai.

Jesada said the first four boys who were taken out are now eating well.

However, another official, Thongchai Lertwilairatanapong, inspector general of the public health ministry, said initial blood tests "showed signs of infection."

The Associated Press reports that the families of the boys "were being kept at a distance because of fears of infection and the emaciated-looking boys were eating a rice-based porridge because they were still too weak to take regular food, authorities said."

The parents were allowed to see their children through glass at the hospital, according to the BBC's Jonathan Head.

Describing the rescue operation's final phase, Narongsak said that divers were resting and replenishing oxygen tanks to store along the treacherous route the remaining boys will take out of the cave.

The plan, he said, was to bring out all four boys and their coach on Tuesday if the weather cooperates.

"If the rain god helps us, then we may be able to work fast," the head of the rescue mission, Narongsak told reporters. "But if the rain god doesn't help, then it could be challenging."

The boys, ranging in age from 11 to 16, and their soccer coach, 25, set out to explore the cave on June 23, but they became trapped after heavy rains flooded passages. Their ordeal has transfixed millions of people, as a massive rescue effort was planned and mounted.

American billionaire entrepreneur Elon Musk tweeted Monday that he had visited the cave and left behind a mini-sub rescue vehicle "in case it may be useful in the future."

"Although his technology is good and sophisticated it's not practical for this mission," Narongsak said of Musk's mini-sub.

Reuters reports that soccer's governing body, FIFA, has invited the boys to the World Cup final in Moscow on Sunday if they make it out in time.