Dec. 26 (Bloomberg) -- A gas attack in a home repair store in St. Petersburg, Russia, poisoned dozens of employees before the start of business today, the Federal Security Service said. Sixty-six workers received emergency care and were sent home.

``At 9:40 a.m. a bang was heard in the tile section of the Maxidom shop on Moskovsky Prospect and gas sprayed out'' of several ampoules, the local branch of the Federal Security Service, or FSB, the main successor agency to the KGB, said in a statement. ``The eyes of workers watered, they began to cough and heart rates increased.''

The gas isn't the kind that's used in biological warfare, it smells like garlic and causes an allergic reaction in certain circumstances, FSB spokesman Valery Kuznetzov said in a telephone interview from St. Petersburg.

An FSB spokeswoman who declined to give her full name identified the gas as mercaptan, a colorless additive used in the energy industry as a warning agent to detect leaks. Kuznetzov said that information couldn't be confirmed and denied a report by the Interfax news agency that said suspicious containers had been found at two other Maxidom outlets in St. Petersburg.

Officials in the press and security departments of the St. Petersburg city government declined to comment.

To contact the reporter on this story: Bradley Cook in Moscow at bcook7@bloomberg.net.

Last Updated: December 26, 2005 09:52 EST