There were 25 new Covid-19 fatalities reported over the past 24 hours, lifting the toll to 703, and 2,636 new cases, raising the total to 119,585, the Public Health Ministry reported on Thursday morning.
There were 1,965 infections detected among the general public and 671 in prisons.
The ministry said 2,268 patients had been diagnosed as recovered and discharged from hospitals on Wednesday.
Since the third Covid-19 wave started at the beginning of last month, there have been 90,722 cases diagnosed, 49,210 of whom have already recovered.
Taweesilp Visanuyothin, spokesman for the Centre for Covid-19 Situation Administration, said later during his daily briefing that 18 men and seven women had died. They were aged 41-94 years.
Eleven died in Bangkok, three in Pathum Thani, two in Chiang Mai and one each in Lampang, Lamphun, Yasothon, Ratchaburi, Phetchabun, Saraburi, Roi Et, Nakhon Si Thammarat and Samut Prakan.
Seventeen of them had hypertension and seven had diabetes and high cholesterol. Other chronic diseases included kidney disease, lung disease, heart disease, obesity, previous stroke and cancer.
Thirteen of them caught Covid-19 from family members and four from colleagues and hospitals. Four others either lived in or visited outbreak areas. Two visited crowded places and one was a taxi driver.
Of the 2,636 new Covid-19 cases over the previous 24 hours, 1,907 were local infections in 53 provinces and 58 were imported.
Of the local infections, 1,385 were confirmed at hospitals and 522 via mass testing. Bangkok continued to log the most local infections at 1,001, followed by 124 in Phetchaburi, 99 in Nonthaburi, 89 in Pathum Thani, 65 in Chon Buri, 61 in Samut Prakan, 57 in Samut Sakhon, 44 in Chanthaburi, 38 in Nakhon Pathom and 30 in Ayutthaya.
Greater Bangkok recorded 1,345 new cases, 71% of new infections nationwide.
He said that of the 671 new cases in prisons, 601 were in Bangkok, 51 in Nonthaburi, 16 in Chachoengsao and three in Chiang Mai.
The total cases in prisons from April 1 to May 20 rose to 13,597. Bangkok had the most number at 8,921, followed by 3,932 in Chiang Mai.
Twenty-four provinces were free of new cases over the past 24 hours. They were Ranong, Phuket, Khon Kaen, Phatthalung, Phitsanulok, Lamphun, Lampang, Roi Et, Nakhon Phanom, Yasothon, Nan, Chumphon, Phayao, Loei, Phrae, Uttaradit, Chai Nat, Nong Khai, Phangnga, Amnat Charoen, Mukdahan, Nong Bua Lam Phu, Bung Kan and Satun.
The 58 imported cases were from Switzerland (1), Japan (1), Tunisia (1), Malaysia (1) and Cambodia (54 Thai returnees including 29 online administrators).
Dr Taweesilp said Thai people were returning from Cambodia, where Covid-19 was spreading, and seven were caught sneaking in illegally over the past 24 hours.
On Wednesday, 42,246 Covid-19 patients were at hospitals -- 17,645 at conventional hospitals and 24,601 at field hospitals. He said 1,213 were critically ill ones and 405 were dependent on ventilators.
Global Covid-19 cases rose by 660,341 in 24 hours to 165.55 million. The worldwide death toll went up by 13,185 to 3.43 million. India logged 276,261 new cases for a total of 25.77 million, and 3,874 deaths, raising the total to 287,122.