A provincial police chief said on Monday that a suicide bomber on foot struck inside a police training center in southern Afghanistan, killing 18 officers and wounding many others. Juma Gul Himat, Uruzgan's provincial police chief, said that the bomber entered the training center in Uruzgan province capital of Tirin Koton. The blast wounded scores of other policemen, seven of them seriously, and several buildings were damaged, Himat said. Southern Afghanistan is the center of the Taliban-led insurgency. The militants have made a comeback after being initially defeated in the US invasion in 2001.