The arrests were made yesterday in Jhal Magsi district of the impoverished province, a police official said today.
The official said two men entered into a gay marriage on Monday while their two friends helped them to perform the Nikah.
The accused told police that they arranged a fake marriage as part of fun but a formal FIR has been registered against them as gay marriage is illegal and a violation of the law in the country, the official said.
It was the first reported case of gay marriage from conservative Balochistan which is rocked by violence.