One of pop star Justin Bieber's tour buses was stopped Sunday by US border agents as it was crossing the Ambassador Bridge to Detroit from Windsor, Canada after a police dog alerted them to the presence of drugs inside the bus.

The bus was on its way to Detroit for Bieber's "Believe Tour", where he was performing at the Joe Louis Arena.  

In a report by Yahoo! omg!, a U.S. Customs and Border Protection spokesperson said, "During the secondary inspection, a K-9 alerted to the presence of drugs and a subsequent search of the bus revealed marijuana and drug paraphernalia. Officers seized the marijuana and paraphernalia and issued a penalty to the driver. The bus and passengers were released without further incident."

News reports confirm that Bieber was not in the bus that night and was most likely in another vehicle. In a news report by Daily News, Bieber was quoted as tweeting Tuesday morning, "I'm a lucky guy". And many speculate he was referring to being able to narrowly escape the drug bust.

This is not the first allegation of marijuana possession for the 19-year-old singer. Just this year, a photo of him surfaced smoking what looked like marijuana for which he later apologized.

Bieber's "Believe Tour" was also plagued by negative news after he was photographed spitting from his Toronto hotel balcony. Incidentally, right below were hordes of fans lined up hoping to catch a glimpse of the star. Reports are unsure whether he actually hit someone with his spit.

In a similar report by Yahoo! omg!, Bieber's rep was quick to dispel speculations that he intended to hit his fans waiting below the balcony, "Justin didn't spit on anyone. In fact, earlier in the day, Justin bought his fans hot chocolate and played them some of his new music. Justin loves his fans."