Iranian police detain four unspecified foreigners over unrest

Iranian police have arrested four foreigners over last month's unrest, Iranian state media reported on Monday, without specifying their nationality.

State media quoted Iranian police as saying the four foreigners had been arrested "in a raid inside their hideout".

Four homemade sound grenades had been found in one of their bags.

Thousands of Iranians are believed to have been killed in a crackdown on anti-government protests last month.

Iran's authorities blame foreign countries for fomenting the violence, the worst domestic unrest since the 1979 Islamic Revolution.

The authorities have been announcing daily arrests of suspected protest ringleaders.

The U.S.-based rights group HRANA said on Monday nearly 50,000 people have so far been arrested.