Another 334 new Covid-19 cases have been reported, 327 local infections and seven imported, raising the total to 29,905.
The figure was up on the 250 new cases announced on Tuesday, a 33% increase.
Apisamai Srirangson, assistant spokeswoman for the Centre for Covid-19 Situation Administration, said on Wednesday that 174 new cases were confirmed at hospitals on Tuesday, and 153 were detected through mass testing.
Bangkok recorded 216 new cases (66% of the daily increment), with 133 found by mass testing (including 126 Thai and two Filipino) and 83 confirmed at hospitals (81 Thai, one Lao and one Indian).
"New cases in provinces were linked to the infections at entertainment places in Bangkok. The present Covid-19 situation is as serious as that which occurred in Bang Khae district and raises serious concerns," Dr Apisamai said.
Samut Sakhon province reported 12 new cases at hospitals (nine Thai and three Myanmar). Nonthaburi had eight new cases confirmed at hospitals (five Thai, two Myanmar and one Vietnamese).
At hospitals, eight new Thai cases were detected in Suphan Buri, six Thai cases in Prachuap Khiri Khan, three Thai cases in Pathum Thani, two Thai cases in Chiang Mai, one Japanese case in Ayutthana, one Thai case in Lampang and one Thai case in Nakhon Pathom.
Also confirmed at hospitals were two Thai cases in Khon Kaen (linked with local entertainment places), 15 Thai cases in Samut Prakan, six cases in Chon Buri (five Thai and one Japanese), one Thai case each in Chanthaburi, Udon Thani, Songkhla, Narathiwat, Phuket and Rayong and 20 cases in Sa Kaeo.
New cases in Bangkok, Samut Prakan, Chon Buri, Nonthaburi, Pathum Thani, Nakhon Pathom and Ayutthaya were linked to infections at entertainment venues in Bangkok. The cases in Sa Kaeo were linked to local entertainment places there, Dr Apisamai said.
Active case finding confirmed 15 new cases in Samut Prakan (13 Thai and two Cambodian) and five Thai cases in Chon Buri.
From Sunday to Wednesday, new Covid-19 cases were reported in 27 provinces, Dr Apisamai said. Since March 11, nine provinces had been free of new cases. They were Phayao, Phrae, Mae Hong Son, Uthai Thani, Bung Kan, Sakon Nakhon, Phangnga, Pattani and Yala, Dr Apisamai said.
The seven imported cases were quarantined arrivals from Sudan, India (2), Pakistan, Switzerland, Japan and the United Arab Emirates.
Of the 29,905 total cases, 28,069 (93%) had recovered, including 11 discharged on Tuesday, and 1,741 were in hospitals. Thirteen patients were seriously ill and seven were using ventilators. The death toll remained at 95.
Global Covid-19 cases rose by 576,636 in 24 hours to 133.02 million. The worldwide death toll was up by 11,802 to 2.88 million. The United States had the most cases at 31.56 million, up 62,283, and the most deaths at 570,260, up 906.