"Seven trawling ships with 24 foreign crew were detained on Tuesday night by IRGC forces due to disregarding the allowed distance to coasts for fishing and violations related to fishing", the IRGC said, as quoted by the Mehr news agency.
The cases have been already referred to court for relevant proceedings, according to the Revolutionary Guards.
Reportedly, the ships caught 222 tonnes of fish.
According to the news outlet, the IRGC had long been warning against illegal fishing in Iranian waters in the Persian Gulf and the Oman Sea.
The detention comes as the situation in the Persian Gulf remains tense after several tankers were attacked in the waterway vital for global oil shipments in summer, prompting the United States to blame the incidents on sanctions-hit Iran and boost own military presence in the region.
Moreover, in July, Tehran seized UK-flagged Stena Impero tanker in the Strait of Hormuz over an alleged breach of international maritime regulations. The move came two weeks after Iran's own Grace 1 oil tanker had been seized by UK marines near Gibraltar over an alleged violation of EU sanctions against Syria. The Iranian vessel was since released, while the UK-flagged ship remains in custody, with seven of its crew members allowed to leave the country earlier on Wednesday.