Thailand has tightened entry rules for foreigners after two new imported COVID-19 cases raised concerns about a possible second wave of outbreak in the kingdom.

The two imported cases involve a 45-year-old Egyptian military crewman and a nine-year-old girl, a family member of a Sudanese diplomat who tested positive for COVID-19 last week.

Centre for COVID-19 Situation Administration (CCSA) spokesman Thaweesilp Wissanuyothin said all diplomats and family members who were previously allowed to undergo 14-day self-quarantine in their residences now have to undergo quarantine at state facilities or alternative state quarantine centres (self-paid hotel quarantine).

"CCSA takes responsibility for the incident. There are many things we did not foresee. This is an important lesson," he said at a COVID-19 daily briefing here today.

Meanwhile, Prime Minister General Prayuth Chan o-cha, who is also the head of CCSA, said the incident was 'unnecessary' and apologised to the public.

"I am sorry and I would like to apologise to the public. This should not have happened. A thorough investigation will be conducted," he said after chairing the weekly cabinet meeting today.

Yesterday, CCSA said one of 31 crewmen on an Egyptian military plane that stopped over in the eastern province of Rayong on July 8 on their way home from Chengdu, China was tested positive for COVID-19.

The crewmen involved were permitted to leave their quarantine facility and wander around, leading to hundreds of locals who were at the mall in Rayong to face home quarantine.

Besides that, the hotel in Rayong where the Egyptian crew stayed has been closed for two weeks. At least 10 schools in Rayong province are closed from today to July 17.

Meanwhile, Thailand has reported seven new COVID-19 cases, all Thai nationals who returned from abroad, and zero fatalities over the last 24 hours, bringing the tally to 3,227 cases and 58 fatalities thus far.

The new patients are six male Thai students who returned from Egypt and one Thai woman who came back from the United States.

Today marks the 50th consecutive day without a local transmission in the kingdom.

-- BERNAMA