Police in Bangkok say at least six bomb blasts went off at a number of locations in the city on Friday, as the Thai capital hosted a key regional security summit, ONA reports citing The Independent.
A seventh device was recovered unexploded, officials said, as the Thai prime minister ordered an urgent investigation to find the perpetrators.
Four people were injured in the blasts, none seriously, according to a central medical facility. Images from one bomb site showed three street cleaners looking dazed and getting treatment from medics.
The first two explosions took place near metro stations in the city centre, just before 9am during the morning rush-hour. The fourth injury occurred in a blast near the 77-storey King Power Mahanakhon tower, one of the tallest buildings in the city.
"I would like to condemn those causing the situation which destroys peace and damages the country's image," said prime minister Prayuth Chan-ocha on Twitter.
"I have instructed officials to take care of public safety and those affected promptly."
Deputy prime minister Prawit Wongsuwan told reporters that police had arrested two suspects, and accused the bombers of trying to "create a situation".
On Thursday police had found two fake bombs near the venue of the meeting of foreign ministers of the Association of Southeast Asian Nations (ASEAN). The meeting was not interrupted.
China's top diplomat Wang Yi and US Secretary of State Mike Pompeoare among the regional and global representatives attending the forum.
It was not immediately clear whether the bombings were designed to target the summit, or if they were linked to Thailand's recent democratic election, in which the country's military junta formally gave up power - but coup general Prayuth remained in office.
And shortly afterwards, a blast was heard at a government complex housing several ministries in the northern part of the city. There has been no claim of responsibility.