Iran has called on Saudi Arabia to swiftly free the three Iranian fishermen who had wandered into Saudi waters because of tumult in the sea and who have been detained by the Saudi coastguard.

The Iranian Interior Ministry made the demand in a statement issued on Wednesday, saying Riyadh had to live up to its legal obligation of returning the fishermen, paying up compensation, and punishing those behind the incident.

Bearing licenses, three Iranian fishing boats had departed from the southern Iranian Bushehr Port last week, the statement explained, adding that, later during the trip, tumultuous sea conditions pushed them into Saudi waters.

One of the vessels managed to return to the Iranian waters, the other two being directed by the waves into Saudi waters, where they came under live fire from the Saudi coastguard, it added.

The statement said the fishermen on board the two boats had no idea they had been pushed across the maritime border and even if they did, they could not do anything about it because they had lost control of the vessels.

The Saudi fire killed one fisherman on board one of the two boats, on which another fisherman finally managed to regain control and return to the Iranian coast, it said, adding that the other vessel, however, was impounded by the Saudi coastguards, who also detained three fishermen on board.

The statement identified the fishermen killed as Mahmoud Siamar, and the three arrested as Hossein Aslani, Sohrab Aslani, and Hossein Zarei.

The ministry said such innocent trespassing by civilian boats is common and had occurred 17 times over the past months in Iran’s territorial waters.

“The boats trespassing [into Iranian waters] were returned to their respective countries [of origin] with goodwill. The opening of fire on fishing boats [by Saudi Arabia] is against humanitarian and Islamic principles,” it said.

On Monday, Saudi Arabia’s Information Ministry said in a statement that Saudi forces had captured and were questioning three members of Iran’s Islamic Revolution Guards Corps (IRGC), “who were intending to carry out an attack on a major offshore oilfield in the Persian Gulf,” according to an Associated Press report.

This is while Saudi Arabia itself had offered a different narrative about the incident some two days earlier, saying merely that the Iranian boats had entered its waters and been shot at.

Iran has rejected the claim, saying the arrested individuals were “simply fishermen” and not IRGC members.