Bahrain says it has arrested 47 suspects and seized explosives in a counterterrorism operation, and has again alleged Iranian involvement in militant attacks.

The kingdom announced the arrests Wednesday night on the state-run Bahrain News Agency. It did not identify those arrested, nor say when the raids took place. It alleged those involved "hold strong connections with terrorist organizations in Iran."

In October, Bahrain announced the seizure of 1.5 tons of explosives and later expelled the acting Iranian charge d'affaires, saying Iran supported militants.

The tiny Arab Gulf nation of Bahrain has faced low-level unrest for more than four years, sparked by widespread 2011 protests among the country's Shiite majority demanding greater political rights from the Sunni monarchy.

Bahrain hosts the U.S. Navy's 5th Fleet.