Of the new infections, 1,930 were domestic transmissions and 10 others were imported, CCSA spokeswoman Apisamai Srirangsan told a press conference.
The capital city Bangkok registered the highest number of new infections with 539 cases, followed by 276 cases in Nonthaburi and 145 cases in Samut Prakan, according to Apisamai.
Since Saturday, Thailand has opened registration for the vaccination program to the elderly and people with critical health conditions. A total of 430,588 people have registered on the first day, the Xinhua news agency reported.
Nationwide, infections in Thailand now stand at 68,984, with 245 deaths, the CCSA data showed.