Several small bombs exploded across Bangkok on Friday injuring three people as the Thai capital hosted a regional summit attended by top diplomats from the United States, China and other world powers.

There was been no immediate claim of responsibility for the blasts. And Thai Prime Minister Prayuth Chan-Ocha has condemned the blasts, claiming the bombing destroyed peace and damaged the country's image.

Government spokesman Narumon Pinyosinwat said Prime Minister Prayuth Chan-ocha had ordered an investigation.

"The situation is being closely monitored and security measures have been tightened. The public is urged not to panic," he said.

The first explosions were heard just before 9 a.m. at two sites near central Bangkok. A third blast was heard shortly afterwards at a government complex hosting several ministries on the northern side of the city. Police said two street cleaners had been hurt by what appeared to be a homemade bomb in the Suan Luang district.

Bomb disposal experts were deployed around the Mahanakorn Tower, owned by the King Power group that counts Leicester City football club among its assets.

Bangkok is currently hosting a regional security meeting of foreign ministers from the Association of Southeast Asian Nations (ASEAN). Chinese State Councilor and Foreign Minister Wang Yi and U.S. Secretary of State Mike Pompeo are attending the forum along with other regional and global officials.

None of the blasts on Friday were in the immediate area of the meeting venue. Thailand's government urged the media to avoid speculation on the motive for the bombings.

On Thursday, Thai police said they had found two fake bombs near the venue of the regional security meeting. The packages prompted a brief security scare but were quickly deemed harmless. It was unclear whether the meeting was the target.

Police said two men have been arrested in connection with the fake bombs.

(With input from Reuters and AFP)