BANGKOK A small pipe bomb exploded near a symbolic location in Bangkok on Wednesday, the eve of the signing of a new constitution that will allow for an election to end military rule in Thailand.
Police said the device had exploded inside a dustbin in the centre of the city close to the Democracy Monument, which has been a rallying point for pro-democracy protests over the decades.
Two street cleaners were taken to hospital with ringing in their ears, but there were no other injuries, police said.
"It's not an act of terrorism or an act to stir unrest," Bangkok police chief Chaktip Chaijinda told Reuters.
Thailand's army seized power in 2014 in the name of ending political turmoil. King Maha Vajiralongkorn is due to sign a new constitution on Thursday as a step towards an election expected next year.
A series of coordinated bombings in Thai tourist resorts last August left at least four people dead and dozens wounded days after a referendum which approved the new constitution.
No group claimed responsibility and the government has not said who it thinks might be to blame.
(Reporting by Panarat Thepgumpanat; Editing by Alison Williams)