Bahrain’s public prosecutor has charged 17 people with forming a militant group and carrying out bombings that wounded security personnel, the state news agency said on Saturday.

The group had set off bombs in the island kingdom’s Maqaba, Al-Janabiya, Budaiya and Qarya vilages, prosecutor Ahmed Al-Hammadi was quoted as saying.

“The members had agreed to set up a terror cell to make explosives and weapons to carry out terror acts, target security forces … and spread panic among people,” he said, according to Bahrain News Agency.

Their trial will begin on March 22 and two of the defendants outside the country will be tried in absentia, he added.

The Sunni Muslim-ruled country, home to the U.S. Fifth Fleet, was swept by unrest in 2011 led by majority Shi’ites demanding political reforms.

There have been a growing number of attacks using explosives, often targeting policemen.