Officials talk to confused Thai passengers after they landed at Suvarnabhumi airport on Friday night. (Photo supplied by Mongkol Bangprapa)

Prime Minister Prayut Chan-o-cha has ordered 152 Thais who landed at Suvarnabhumi airport on Friday afternoon and refused to enter state quarantine to report themselves before 6pm on Saturday so that they can be put into state facilities.

A total of 158 Thais — 103 from Japan, 11 from Qatar and 44 from Singapore — landed at the airport at 1pm on Friday, Dr Taweesin Visanuyothin, a spokesman for the government's Centre for Covid-19 Situation Administration, said on Saturday.

But only six of them agreed to be sent to a place prepared by authorities, which is a hotel in Bangkok.

The remaining 152 refused to cooperate, saying they had not been informed about it in advance, and left for home.

After a meeting on Saturday, the Centre for Covid-19 Situation Administration decided to put all of thses returnees in state quarantine.

They must contact the Emergency Operation Centre (EOC) at Suvarnabhumi or the Damrongtham Centre in their provinces.

Dr Taweesin stressed the government had their personal information and could track them down and warned about legal action.

He also urged people close to them to self-isolate for 14 days.

Thais in transit to return home should also contact Thai embassies for advice and they must agree to be put in state quarantine once landing, he said.

The commotion at the airport on Friday occurred mainly because of the transition of rules.

The group consisted of Thais who were able to fly home because they had obtained all the necessary documents — fit-to-fly certificates issued within 72 hours before boarding and letters from embassies confirming they are Thai nationals seeking to return home — when they boarded planes.

Gen Prayut announced on Thursday evening all travel to the kingdom by both Thais and foreigners would be banned until April 15, effective immediately. After that period, he said all arrivals must be quarantined at state facilities.

As a result, when this group of Thais landed and were told they must be quarantined at state facilities, they protested, reasoning they had not been informed beforehand by Thai embassies that this was part of the requirements.

While recognising the importance of quarantine, they assumed they could do it at home. Some even claimed to have already booked hotel rooms for the purpose.

The Foreign Ministry on Saturday denied it did not follow the government's order by enabling this group to return home, saying the prime minister’s announcement came after the embassies already issued the letters for them.

Ministry spokesman Cherdkiat Atthakorn said that after Gen Prayut’s announcement banning all travel to Thailand on Thursday, the embassies stopped issuing the letters and shut down the online application for the purpose.

He added several Thai embassies also informed in their announcements that Thais returning home would be quarantined at state facilities for 14 days without exception. The online form Thais abroad used to apply for the letters also mentioned the quarantine.

Authorities have prepared facilities in Sattahip and two hotels in Bangkok for state quarantine.

As a result of the confusion on Friday, the Civil Aviation Authority of Thailand issued an announcement a few hours later temporarily banning all passenger flights from landing in Thailand until Monday to prevent further problems. It took immediate effect.

The exceptions are state or military aircraft, emergency landing, technical landing (with no disembarkment), humanitarian aid or medical and relief flights, repatriation and cargo aircraft.

Passengers on aircraft leaving other airports before the announcement took effect shall come under the communicable disease and the state of emergency laws. They must be quarantined for 14 days.

A military source said Maj Gen Kosol Choojai, who was in charge of the EOC at Suvarnabhumi and allowed the 152 passengers to go home, was replaced by Gen Paripat Palasin. The major general will face a probe for his handling of the situation.