An Iranian fisherman was killed by Saudi Arabia's coast guard last night, Iran's state TV said Saturday.

The IRINN TV news channel reported that local sources from Boushehr province said that Saudi coast guard officers fired at two Iranian fishermen on Friday, killing one.

Several Iranian news websites also reported that two Iranian boats were shot at as they approached a Saudi oil rig.

Mohammad Aghababaei, an official in Iran's interior ministry, said "For now, we are following up on this event until the details were cleared," according to the channel's website.

Predominantly Shiite Iran and Sunni Saudi kingdom have been regional rivals and support opposite sides in conflicts across the Middle East, including the wars in Syria and Yemen.

Iran and Saudi Arabia severed diplomatic ties in 2016, and twin Islamic State-claimed attacks on Iran's parliament and the tomb of its revolutionary leader last week flared tensions between the two nations to a new high.