Health authorities reported 34 new Covid-19 fatalities on Friday and another 3,759 cases, bringing the accumulated toll to 954 deaths and the number of cases since the start of the pandemic to 144,976.
The Centre for Covid-19 Situation Administration said 2,465 of the new infections were in the general population and 1,294 in prisons.
The CCSA said later in its afternoon briefing that Bangkok again led the fatalities with 24 cases. It said two of them were prison inmates but gave no other details.
Samut Prakan registered three deaths, with two in Nakhon Si Thammarat and one each in Chon Buri, Nakhon Ratchasima, Nakhon Sawan, Tak and Roi Et.
The capital also topped the number of new infections, 973, followed by Phetchaburi (658), Samut Prakan (221), Nonthaburi (102) and Samut Sakhon (55).
CCSA assistant spokeswoman Apisamai Srirangson said a close watch was being kept on 39 clusters in 27 districts of Bangkok, including three new communities, to prevent the virus spilling to other areas.
There were 18 infections reported in people arriving from five countries, she said.
Eleven were Thais returning from Cambodia through the Aranyaprathet checkpoint in Sa Kaeo, along with one Thai from Malaysia, four Thais from India and one Thai from Oman.
A Philippine crewman was also found infected with the virus and he was quarantined on board his ship, which arrived from Indonesia and was anchored off the coast of Songkhla.