An explosion hit a McDonald's restaurant in St. Petersburg, injuring at least six people, partially destroying a ceiling and breaking windows, an emergency official said. The Interfax news agency said a bomb had detonated.
The blast occurred around 8:30 p.m. (1730GMT) Sunday at one of the restaurant chain's outlets in the city center, said Irina Andriyanova, a spokeswoman for the federal Emergency Situations Ministry. Preliminary reports said six people were wounded. Four of them were hospitalized with various injuries, including concussions and cuts from flying glass, the AP reports.
Part of the restaurant's ceiling collapsed and several windows were shattered or blown out. Dozens of police kept reporters and onlookers away from the scene along Nevsky Prospekt, St. Petersburg's main avenue, as investigators and security agents combed the sidewalks for evidence.
Ekho Moskvy radio, citing witnesses, said the blast went off in the hand bag of one of the patrons in the restaurant.
There was no official indication of whether the explosion was a terrorist or criminal act, or whether it was accidental. However, Interfax, citing an unnamed St. Petersburg police official, said investigators were considering "hooliganism" as the main theory behind the blast.
St. Petersburg police officials referred all questions to prosecutors, who could not be reached for comment Sunday evening.
The St. Petersburg news Web site www.fontanka.ru said a German citizen was among the injured.
McDonald's restaurants in Russia have been targets of both criminal gang disputes and terrorist attacks in the past.
In 2002, a car bombing at a McDonald's restaurant in Moscow killed one person and injured eight. Several Chechen men were later convicted in the blast, which prosecutors said was part of a series of attacks planned by Chechen rebels.
In 1998, a small bomb exploded at an unfinished McDonald's restaurant in another part of St. Petersburg. It was unclear whether investigators ever determined the motive behind that blast. The restaurant's construction was opposed by residents of buildings that were razed to make way for it.