As many as 40,000 Thai and foreign revellers joined the water fight on Bangkok’s backpacking hub on the first day of the Songkran festival.
As the crowd built up in the evening, police manning checkpoints were ordered to close off the street and prevent more visitors from entering to reduce congestion in the area.
Authorities had forecast large crowds at Khao San for the first Songkran celebrations since Covid-19 restrictions were lifted.
Local businesses expect to see 30,000 to 40,000 Thais and foreigners per day visit the street over the Songkran holiday.
Khao San Road runs for just 400 metres and has main entry and exit points at each end, plus several small alleyways leading from the street.
Concern over the potential dangers of overcrowding at large public events is riding high following a deadly stampede in South Korea last year.
The Itaewon tragedy, which killed 156 people and left 172 injured, occurred after more than 100,000 partygoers and tourists were crushed in a narrow alleyway of the nightlife district in Seoul during Halloween celebrations on October 29.
Khao San has been closed to motor traffic from noon to 8pm for water fights through Saturday.
Revellers are still able to participate in the Songkran party on the road today and tomorrow.
A squad of 100 police officers and civil defence volunteers has been sent to Khao San this week to ensure security and public safety among the crowds.
Seven screening checkpoints, three first aid stations, four ambulances and three emergency exits have been deployed in the area.
Officers from the local Chana Songkhram police station said they will be checking for weapons and smuggled alcohol. High-pressure water guns, coloured powder, and nudity are also banned at this year’s Songkran parties.