MANAMA, Bahrain (AP) -- A bomb blast in Bahrain killed three policemen as they were dispersing "rioters and vandals" on the outskirts of the capital Manama, authorities said Monday in an escalation likely to increase tensions between security forces and hard-line protesters.
The Interior Ministry said in a statement that the police were killed Monday in what it called a "terror bombing attack," and that initial indications suggest the bomb was planted near a lamp post and was detonated remotely. Two other explosions occurred nearby and another bomb was defused, the ministry said.
Among those killed in the blast was a police officer from the United Arab Emirates deployed to help bolster security in the tiny island kingdom.
In Bahrain's three-year uprising, a Shiite-dominated opposition movement is demanding increased political rights from the Sunni monarchy. The country is a small, Western-allied island kingdom off the coast of Saudi Arabia that is home to the U.S. Navy's 5th Fleet.
While mainstream opposition leaders have urged their followers to keep the demonstrations peaceful, young protesters armed frequently clash with riot police in running street skirmishes.
Some radical anti-government factions have been increasingly using bombs targeting government forces. The weapons typically do not have the force of explosives used by insurgents in places such as Iraq or Syria, though they have resulted in a number of deaths.
King Hamad bin Isa Al Khalifa called for a day of mourning on Tuesday to mark the officers' deaths and extended and ordered security forces to bring those responsible to justice.
"The King directed all competent state agencies to enforce the law on the instigators of the abominable terrorist blast and take all necessary measures to ward off such acts of terror on all levels," the Royal Court said in a statement carried by the official Bahrain News Agency.
The UAE's state news agency WAM identified the Emirati killed as 1st Lt. Tareq Mohammed al-Shehi. It said he was serving in Bahrain as part of the "Gulf Waves Force" deployed under a joint security cooperation agreement among Gulf Cooperation Council States.
The GCC includes Saudi Arabia, the UAE, Bahrain, Kuwait, Qatar and Oman. Saudi Arabia and the UAE sent forces to Bahrain to help its Sunni monarchy quell the Arab Spring-inspired protests soon after they broke out in February 2011.
The main opposition groups condemned Monday's blast, saying that they are against all kind of violence. Witnesses reported seeing attackers vandalizing offices of the main Shiite opposition bloc, al-Wefaq, soon after the blast in apparent retaliation for the attack.
Associated Press writer Adam Schreck in Dubai, United Arab Emirates, contributed to this report.
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