"Locally-made bombs." This apparently is a signal that Iran is not involved this time, or at least that its involvement is not directly known. Sunni/Shi'ite Jihad in Bahrain: "Five bomb blasts hit Bahrain capital, two workers killed," from MSN News, November 5 (thanks to Kenneth):
DUBAI - Five home-made bombs went off in the Bahraini capital of Manama on Monday, killing two street cleaners and wounding another worker, the state news agency said, describing the explosions as "terrorist acts".
Police have been targeted by explosions several times this year, as the government has stepped up efforts to quell an uprising that has simmered since democracy protests broke out in early 2011.
But bombs targeting civilians are rare in the kingdom, where the Sunni Muslim Al Khalifa family, a U.S. ally, rules over a majority Shi'ite population.
The explosions on Monday took place in the Qudaibiya and Adliya districts of Manama, the BNA agency said, citing a police official. In one incident, a man died after kicking an object which then blew up, it said. It described the explosives as "locally-made bombs".
An Interior Ministry statement on Twitter said the two dead men and the wounded man were Asian workers....