Masked gunmen entered a bingo parlor in San Francisco's Potrero Hill neighborhood last Tuesday night and robbed the patrons.

According to eyewitnesses, four gunmen -at least three of them masked- entered the bingo parlor at Chesar Chavez and Pennsylvania Avenue about 10 p.m.

Police was still at the bingo hall at midnight, investigating the hold-up.

Witnesses said the robbers ordered everyone to get on the ground, then took players' money and personal values and fled the scene.

There was no immediate notice as to whether anyone was injured in the incident or if police had made any arrests.