A man exploded a gas canister near a tourist bus in a town east of the Moroccan capital Monday, the Interior Ministry said. The man, whose arm was blown off in the explosion, had apparently been targeting the bus, said an Interior Ministry official who asked not to be named, citing the department's policy. No other casualties were reported. The attack in Meknes, 130 kilometers east of Rabat, came as Moroccan authorities have been cracking down on suspected extremists following suicide bombings earlier this year. "The individual, who was going toward the bus in a very populated neighborhood, was not able to reach his objective due to the vigilance of the driver," state news agency MAP reported. Neither the ministry official nor the agency report gave any more details on the explosion or the bus driver's actions. An investigation into Monday's blast has been opened, and security services were searching for two suspects seen talking to the would-be bomber prior to the failed attack, the official said. Authorities have tightened security since putting the country on high alert last month, including setting up roadblocks around some cities and deploying more police officers on the streets. In March, a suicide bomber blew himself up in a Casablanca cyber cafe, and investigators later uncovered an alleged plot targeting tourist sites across Morocco. Police cornered four suspects, shooting one dead and prompting the other three to blow themselves up to avoid capture. The blasts killed a policeman and injured 21 other people. Suicide bombings in 2003 in Casablanca killed 45 people and stunned this relatively moderate Muslim country, a popular vacation spot. Since then, Moroccan authorities have cracked down on suspected terrorist activity, making regular arrests.