Thailand on Sunday reported 1,940 new coronavirus cases amid a deadly third wave of the virus.
The Health Ministry recorded a second day of 21 deaths, the highest daily number of fatalities since the pandemic began.
The country was largely able to control the virus early in the pandemic through shutdowns and strict border controls.
But a deadly third wave that begin in early April includes the highly transmissible B.1.1.7 variant and has accounted for about half of its total cases and deaths.
Sunday's numbers brought the country's total confirmed infections since the pandemic began last year to 68,984.
Total deaths are now at 245.
Bangkok led fatalities with eight victims, seven of whom had been in close contact with infected family members, according to the Centre for Covid-19 Situation Administration (CCSA). Chiang Mai recorded the second most deaths – four – followed by two each in Chon Buri and Lamphun, and one each in Nakhon Pathom, Nakhon Sawan, Rayong, Tak and Udo Thani.
The number of new infections in Bangkok on Sunday was the second lowest in a week -- after the 417 cases recorded on Friday -- while the new caseload in Chiang Mai also dropped for the fourth consecutive day.
Assistant CCSA spokeswoman Dr Apisamai Srirangson said people should not become complacent and said the decision to ban dine-in customers in eateries would help reduce the numbers.
Three of the imported cases arrived from Egypt, and one new case each flew in from Austria, South Korea, Norway, India, Pakistan, South Africa and Sudan, the CCSA said. The case from India was an Indian national who entered Thailand on April 22 before the kingdom slapped a ban on non-Thai arrivals from the stricken country on Saturday.
Thailand has vaccinated nearly 1.5 million people so far, mostly medical workers and vulnerable people, using imported doses of China's Sinovac and the AstraZeneca vaccines.
A mass vaccination programme is to kick off in June with locally-manufactured AstraZeneca doses.
Vaccine registration opened to the public this weekend with a goal of inoculating 70% of adults in the country of more than 66 million people.