HOUSTON -- Bars in Houston are supposed to close no later than 2 a.m., but some operate outside the law. So, when Houston police launched a raid of one of the most popular after-hours bars in town, 11 News was invited to tag along.

The raid took place early Saturday morning, but planning for the operation began months ago.

At 3 a.m., an hour after what is supposed to be closing time, dozens of uniformed and undercover narcotics officers stormed into the The Pink Monkey in downtown.

The club, located on Franklin at Milam, actually sits below street level along the banks of Buffalo Bayou.

When cops busted in the door, an estimated 500 people were there.

A Houston Police Department captain started the raid with instructions via a mega horn.

“As soon as we can get you lined up (and) tested to see if you are intoxicated or one of the suspects wanted for a criminal investigation… If you're not one of them we will release you,” he hollered.

HPD says its investigation was necessary because of all the complaints it had received.

A drug related death allegedly occurred at the club and a woman who reportedly had her drink spiked, was sexually assaulted. The Pink Monkey, police said, had become a haven for drug dealers and after-hours drinking.

As soon as police arrived some people, allegedly trying to avoid arrest, tossed their illegal drugs.

Police found cocaine, Xanax, ecstasy and marijuana dumped into a couple of trashcans or simply tossed on the floor.

Around 5 a.m., two hours into the operation, police and EMS personnel are distracted when they hear a loud crash outside. Turns out a man driving a stolen ambulance plowed into two patrol cars and another ambulance that were part of the club raid operation.

The suspect had to be cut out of the ambulance before he was taken to the hospital and then eventually to jail.

Once those anxious moments were over, officers go back to work at the Pink Monkey where more than 160 people were processed and then taken to off to jail.

When it is all done, the operation goes down as one of the largest club raids the city has ever seen.