MANILA, May 9 (Xinhua) -- Four policemen were injured, three seriously, when a roadside bomb exploded in the southern Philippines Cotabato City on Tuesday, police said.
Police said the improvised explosive device (IED) went off around 10:15 a.m. (local time) in front of a public market and a school in Rajah Buayan town in Maguindanao province, wounding the policemen on board a police patrol car.
Initial investigation showed the IED was detonated using a mobile phone.
The wounded policemen were reportedly in the area to attend a conference on anti-illegal drugs campaign launched by the town officials.
According to the police, the blast may have been carried out to retaliate last week's police anti-narcotics operation in the town that killed a mother, her two children and a drug pusher.
