A policeman was killed and seven people, including a child, injured in an explosion Friday evening in a predominantly Shia district of Bahrain's capital Manama, authorities said. Four police officers were among the injured, one of them seriously, Information Minister Isa Abdulrahman Al Hammadi told AFP. Two parents and their child were also hurt in the blast in Karanah suburb, he said. The minister said the explosives used in the apparent bomb attack was "very similar" to that seized by authorities last month which "came from Iran". ALSO READ: Bahrain foils terror plot against Saudi, bomb-making materials seized In July, Bahraini authorities declared they had foiled an attempt to smuggle weapons from Iran. A few days later, two police officers were killed and six others injured in a bomb attack on Sitra island outside Manama. - Reuters Bahraini authorities said earlier this month they had arrested five suspects over the attack. ALSO READ: 2 policemen killed, 6 wounded in Bahrain bomb attack Police chief Major General Tariq al-Hasan said the suspects had links to Iran's Revolutionary Guards and the militant movement Hezbollah. Bahrain frequently accuses Iran, of backing demands by members of the kingdom's Shia majority for political reforms. The tiny but strategic US ally has seen frequent unrest since an uprising four years ago demanding a constitutional monarchy.