The nine blasts at busy bus junctions and shopping malls, in various places led to the cancellation of the celebrations.
Reuters adds: Two more bombs, including one near a major shopping mall, hit Bangkok today, wounding at least 10 people, 8 of them foreigners, a Health Ministry disaster centre official said.
The attacks came around midnight, just a few hours after at least six other small bombs killed two people and wounded more than 20, shocking the Thai capital into cancelling New Year countdown celebrations.
There was no immediate claim of responsibility for the bombs, which went off within about an hour and included one planted under a seat at a bus stop outside a shopping mall which wounded 15 people, two seriously, they said.
''There was a big bang and people started screaming and running.
I saw people with blood all over their legs and faces,'' said Chalermsak Sanbee, 17, who was standing near the bus stop.
Another went off near a police booth, wounding two people, and a third was placed in a trash can at a market in the port district and wounded five, including a 10-year-old child, police said.
The bomb outside the shopping mall near the Victory Monument in the centre of the Thai capital appeared to have caused the largest number of injuries, they said.
Another went off in the parking lot of a shopping mall on the road to Bangkok's new airport and police closed the centre down, but plans for the New Year countdown in the city's main shopping district were going ahead with increased security.