Five blasts were heard in the city of Kherson early on Wednesday, Russian media reported, adding that according to unofficial information air defence systems were launched.
Kherson, the administrative centre of the broader Kherson region, was one of the first cities to fall to Russian forces after they launched their invasion in Ukraine in February.
Earlier on Wednesday, Ivan Fedorov, the exiled mayor of Russian-controlled Melitopol in the south of the Zaporizhzhia region, said on the Telegram messaging app that there was a powerful explosion in the city.
RIA reported, citing local Russia-installed police, that a device exploded near the city's central market. There were no casualties, RIA reported.
Reuters was not able to immediately verify the reports.
(Reporting in Melbourne by Lidia Kelly; Editing by Kim Coghill)