An Iranian news agency says the country's coast guard has seized two Saudi fishing boats after they allegedly strayed into Iranian waters.

The Tuesday report by the semiofficial Fars agency quotes the local coast guard commander in southern Iranian port of Bushehr as saying the guard detained all 10 of the boat's crew members, all of them Indian nationals.

Fars says Iran released another Saudi fishing boat and its four crew members after it briefly seized the boat and its crew last week.

Last week Saudi Arabia's coast guard detained 21 Iranians on two fishing boats on similar charges.

From time to time Iran and other Gulf states detain fisherman who cross into territorial waters.

Sunni Muslim Saudi Arabia and Shiite Iran are bitter regional rivals.