BANGKOK — A large explosion rocked a central Bangkok intersection during the evening rush hour, killing at least three people and injuring 25 others, police said.

The cause of Monday’s explosion, which sounded like a loud thunderclap to people living nearby, was not immediately known. Police said the injured included some foreigners.

An Associated Press reporter at the scene said he saw one body and body parts. A reporter for the television station Thai PBS said he counted 12 bodies at the scene.

The explosion took place at the Rajprasong intersection, which was the centre of many contentious political demonstrations in recent years. It appeared to have occurred in front of the Erawan Shrine, a tourist landmark also popular with Thais.

Thailand’s capital has been relatively peaceful since a military coup ousted a civilian government in May last year after several months of sometime violent political protests against the previous government. However, there has been some tension in recent months as the ruling junta has made clear it may not hold elections until 2017 and wants a constitution that will allow some type of emergency rule to take the place of an elected government.

Car bombs are almost unknown in Bangkok, but have been used in southern Thailand, where a Muslim separatist insurgency has been flaring for several years.