The head of the Central Jakarta police, Harry Kurniawan, said Tuesday that an investigation has been launched following the explosion, Reuters reported.
Indonesia’s Detik media company said on Tuesday that the explosion took place at the National Monument in Jakarta’s Merdeka Square.
Indonesian Kompas TV said, citing national police spokesperson Argo Yuwono, that at least one person has been injured in the explosion.
The Straits Times said, citing Jakarta police, that two military servicemen were injured in the blast, which was caused by a "smoke grenade."
At the same time, according to multiple local media reports, the source of the explosion remains unknown.
No further details were immediately available.