A homemade bomb exploded in a cafe in Moscow's Kudrinskaya Square, killing three people and injuring 21. File Photo by Yuri Kochetkov/EPA

Aug. 1 (UPI) -- Three people were killed and 21 injured when a homemade bomb exploded in a Moscow cafe Saturday, officials said.

Russia's National Anti-Terrorism Committee said the explosion happened about 8:10 p.m. local time when a woman attempted to enter the Balzi Ross restaurant in Kudrinskaya Square.

The woman had been carrying an improvised explosive device when she was stopped by a guard, state news agency TASS reported.

She was killed in the blast alongside the guard and a cafe customer.