Inside of O.T Genasis' birthday party was a joyous celebration, but outside looked like a SWAT assembly.

O.T. was celebrating his 31st birthday early Wednesday night at Pinz in the Studio City section of Los Angeles, California, with friends including Miguel, Tamar Braxton, Nelly, and his girlfriend Malika Haqq. Things inside were happy and celebratory, with even a birthday serenade from Tamar, but unbeknownst to the guests, someone had made a serious call to the police.

According to law enforcement sources, someone called the police late in the night to report two people at the party were flashing guns and threatening each other. The cops arrived in the alley quickly, with shotguns locked and loaded, and even a police helicopter was called in for the potential threat. The police searched the premises and detained a few people inside, but ultimately no weapons were found. Law enforcement sources also told TMZ that surveillance footage reviewed from Pinz did not show any of the guns that were reported. No one was arrested.

Party attendees tell TMZ they weren't even aware of the cops until the party began to wrap up. It's unclear who called the supposed threat into the police department.

Source: tmz.com