Security forces in Iran have arrested journalists from at least four Iranian newspapers and one news agency over the past few days and accused them of consorting with hostile foreign news media, the state-run press reported Monday. Iranian rights advocates called the arrests part of a broader campaign of intimidation to forestall political unrest before the presidential election in June.

The official accounts did not clarify how many journalists had been arrested, the precise nature of the accusations against them or when they might be formally charged. The Committee to Protect Journalists, a media advocacy group based in New York, said at least 11 journalists had been seized, calling the crackdown the largest on Iranian news media since the unrest that swept the country four years ago.

Accounts by the Mehr news agency and other official news outlets said many of the journalists had been taken into custody on Sunday after the raids on the outlets, all of which are regarded as reform-minded. One of the newspapers, Etemad, is close to a former president, Ali Akbar Hashemi Rafsanjani, and had been raided the previous day as well.

None of the arrests were reported by the raided organizations themselves. Some Iranian journalists said the omissions appeared to reflect fears of further antagonizing the Revolutionary Guards and affiliated security forces whose loyalties lie with the supreme leader, Ayatollah Ali Khamenei.