"The presence of foreign forces cannot be acceptable and will make the situation more complicated and difficult," Ramin Mehmanparast said at his weekly press conference broadcast on state television.

Armed forces from Saudi Arabia and the United Arab Emirates rolled into Bahrain on Monday to help the Manama government deal with pro-democracy protesters.

Television footage showed convoys of unmarked, desert brown armoured vehicles crossing from Saudi's Eastern Province into Bahrain, the home of the US Fifth Fleet.

"Basically, we do not think it is right forces to other countries, specially Persian Gulf countries, to be presented or intervene in Bahrain's situation," Mehmanparast said.