Thai authorities suspect a bomb that exploded in a pickup truck killing five anti-drug police officers was the work of drug traffickers, officials said. The powerful explosion Wednesday sent the truck flying from the roadside into a canal in the Raman district of Yala. Five of six Thai drug suppression officers riding inside a second vehicle were killed. Authorities said the truck bomb attack may have been retaliation for recent arrests of drug-trafficking suspects, the Bangkok Post reported.