According to a Guardian reporter, the rescue official has clarified that the stronger boys among the trapped group are due to come out first.

The rescued boys are all in quarantine. A medical expert spoke to the BBC's Victoria Derbyshire programme about the risks they might face.

It's dark, muddy and filled with twisting narrow passages. Our colleague Nick Beake went into another cave in the region earlier this week to see what it feels like.

It's unclear when the rescue operation is due to end, but a rescue official has said they will "hopefully... have good news in a few hours".

The operation on Sunday was paused just before 21:00 local time (14:00 GMT).

The BBC's Jonathan Head has been in Chiang Rai since we first heard the boys were missing. He's tweeted:

The central focus of the rescue operation has been the 12 boys, but Twitter users are applauding the efforts of the boys' coach Ekapol Chanthawong.

His name has begun to trend on the site - where you might expect condemnation there's incredible support for him.

"At 25, this coach is practically still a kid too," wrote one user, external.

"But he's obviously been a great inspiration to the 12 boys whose morale seem to have never gone down despite what they have endured. Great respect to him."

"I use pride to help deal with my sorrow."

A funeral was held at the weekend for Thai diver Saman Gunan, who died trying to get supplies to the group in the cave.

His wife and father spoke movingly to Wasawat Lukharang of BBC Thai about their loss and their immense pride.

The death of a former Thai navy diver has underscored the dangers behind the rescue operation.

Petty Officer Saman Gunan was returning from a mission to supply air tanks when he ran out of oxygen himself.

His colleagues said they would "not let the sacrifice of our friend go to waste".

Image source, AOT Bike Club

The second phase of the rescue operations officially kicked off at 11:00 local time (04:00 GMT) on Monday.

Oxygen supplies and equipment have been replenished according to plan.

However, officials have refused to comment on the order in which the boys will be brought out.

"We have not been told which child has been brought out," the father of one of the trapped boys told Reuters.

"We can't visit our boys in hospital because they need to be monitored for 48 hours."

The BBC's Frances Mao in Sydney says Australia has sent a team of police divers and independent experts to the operation and Australian media have focused on one doctor in particular.

Cave-diving expert Dr Richard Harris, 53, issued the advice to bring the weakest boys out first, say media reports.

The anaesthetist from Adelaide has more than 30 years diving experience, and previously worked at a state emergency service. He has also led cave retrieval missions before, the Adelaide Advertiser newspaper reported.

“The combination of his medical knowledge and his cave diving skills was clearly [why] the British guys requested that he come as well,” one of his former colleagues told the Australian Broadcasting Corp.

The boys haven't eaten a proper meal in two weeks. Some of them have now asked for Pad Krapao, according to officials.

That's a basil rice dish, usually stir-fried with pork or chicken - and topped with a crispy fried egg. Good choice, boys.

Monday's rescue operation team headed in earlier than expected, according to Narongsak Osottanakorn, who is heading the search efforts.

"We believe we're ready like we were yesterday," he told reporters at a press conference.

Here's a quick recap of all that's happened:- Twelve boys and their football coach were trapped in the Tham Luang cave in northern Thailand since 23 June.

- They were found by two British rescue divers last week, but it wasn't until Sunday that the mission to bring them out began.

- The first boy emerged from the cave at 17:40 local time (10:40 GMT) on Sunday.

- All those already out have been taken to the hospital in Chiang Rai, about an hour away.

- The rescue operation involved 13 foreign divers and five Thai navy SEAL divers.

- It was called off last night to give divers time to replenish oxygen supplies.

Image source, FACEBOOK/EKATOL

The trip out of the cave is a long one - said to take around five hours even for experienced divers.

Some of the boys cannot swim, making the rescue mission even more complicated.

The boys are said to be using a "buddy diving" system, where each boy is accompanied by two divers, who will carry his air supply. The process out of the cave involves a mixture of walking, wading, climbing and diving along guide ropes which are already in place.

The four boys who were rescued last night are now in quarantine, according to officials speaking at a press conference in Chiang Rai.

Authorities are still discussing when parents will be able to meet their children.

The story of the trapped boys has gripped not only Thailand but people around the world.

Well-wishes and encouragement has been pouring in on social media, both for the boys and the rescue team involved.

It's still unclear which four people were rescued from the cave on Sunday.

"We heard four boys are out but we do not know who they are. None of us has been informed of anything," the mother of one boy told AFP.

"I am still waiting, keeping my fingers crossed."

Divers went in to the Tham Luang cave at around 10:00 local time (03:00 GMT), a source close to the rescue efforts told the BBC's Jonathan Head.

According to the source, there was concern that heavy rains yesterday might have raised water levels inside the cave, making the already tricky operation even more difficult.

Welcome back to the BBC's live coverage of the Tham Luang cave rescue in Thailand.

A source close to the operation has told the BBC that after a break overnight, rescuers resumed their efforts mid-morning.On Sunday, four people were rescued from the cave in the northern region of Chiang Rai - it's not yet clear who they were. Nine people remain trapped in the cave, awaiting rescue.