Iran's intelligence minister says Sunni extremists arrested last week were planning 50 bombings in the capital.

Mahmoud Alavi was quoted by the semi-official ISNA news agency Tuesday as saying that 10 "terrorists" were arrested in Tehran and three border provinces. He did not specify which border.

He says the suspects planned to carry out suicide attacks and other bombings in heavily-populated parts of Tehran. He says authorities confiscated 100 kilograms (220 pounds) of explosives and thwarted the delivery of another 1,000 kilograms.

Iran said Monday it had broken up one of the "biggest terrorist plots" ever on its soil.

Alavi says investigations into the plot are still being carried out inside and outside Iran, without elaborating.