Bangkok, Dec 24 (IANS): Thailand on Thursday announced its decision to tighten restrictions to contain the spread of Covid-19, with new cases detected in more than one-third of the country's provinces.

Thailand will now adopt different regulation measures nationwide according to risk levels and caseloads, with its 77 provinces classified into four categories, namely the highly-controlled, controlled, under-high-surveillance and under-surveillance, reports Xinhua news agency.

Natapanu Nopakun, the Foreign Ministry's deputy spokesperson, told a daily briefing that the highly-controlled zone marked by a high infection rate, with Samut Sakhon province, which is under lockdown, being the only one so far, demands the setting-up of a field hospital and checking points as well as restrictions imposed on movements and New Year celebrations.

In the controlled zone, with Bangkok being the only one, residents are required to avoid mass gatherings and New Year celebrations, according to him.

Thailand reported 67 new confirmed cases on Thursday, bringing its total tally to 5,829, with fatalities remaining at 60, according to data released by the Centre for the Covid-19 Situation Administration.

The latest flare-up of infections was first detected at a seafood market in Samut Sakhon province near the capital Bangkok after a 67-year-old vendor was confirmed to be infected.

Cases connected to the seafood market have been reported in 27 other provinces, including Bangkok, and the number is fluctuating, Natapanu said.

He however, said that despite the spike the Covid-19 situation remains controllable in Thailand.

On December 19, Thailand reported 548 new cases, marking the highest daily spike.