At least two people were injured after several small explosions rocked three locations in the ASEAN host city of Bangkok in Thailand in the early hours of Friday.

“Two women sustained injuries,” in one explosion just outside the city centre, the Erawan Emergency Centre responders told AFP.

A second explosion shattered glass near a famous downtown skyscraper, the police said.

A senior police officer said two street cleaners were injured by what appeared to have been a homemade bomb in the Suan Luang district.

Thai police further said that they were investigating the cause of the explosions. Some explosions were heard at a government office and others near at least two other sites near central Bangkok.

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

Police said that two men was arrested in connection with the fake bombs.

Prime Minister Prayut Chan-O-Cha was told of “the bombing incidents and has ordered an immediate investigation”, spokeswoman Narumon Pinyosinwat said,

“Security measures have been tightened. The public is urged not to panic”, Pinyosinwat added.

Bangkok is currently hosting a regional security meeting of foreign ministers from the Association of Southeast Asian Nations (ASEAN) and their counterparts from world powers including the United States, China and Russia.

External Affairs Minister S Jaishankar is also in Bangkok to attend the meeting of foreign ministers from ASEAN.