(KMOV) -- Four suspects are still on the loose after an ATM armored vehicle was stolen early Monday morning.
St. Louis police tell News 4 that an ATM Solutions armored vehicle was stolen around 5:00 a.m. on Monday. The robbery happened in the 3700 block of Grandel in midtown St. Louis near the Fox Theatre.
Police are still looking for four men who allegedly took off in the vehicle. The men were wearing masks and were heavily armed.
St. Louis Police Captain Michael Caruso says that this heist was carefully planned.
Employees at the ATM Solutions building tell St. Louis police that a security officer reported to work around 5:00 a.m. and as he was entering the building, the four masked men forced their way inside. The men were armed with assault rifles and handguns.
Witnesses say the suspects disarmed the security officer and waited for a second security to arrive. Two people are needed to open the safe that stores the money.
The second security officer arrived around 5:30 a.m. and when he entered the building he was confronted by the suspects. The suspects took the second guard's weapon as well.
According to employees, the two guards were then forced to open the safe. The suspects then tied-up the guards.
Police say the suspects loaded an undetermined amount of cash into one of the company's armored vehicles and took off.
Around 6:00 a.m., a supervisor arrived at work, found the two guards tied-up and contacted police.
The armored vehicle was found around 7:30 a.m. in the 4400 block of Evans.
Police say that a black Pontiac Grand Am that may have been used in this incident was found in the 3700 block of Dr. Martin Luther King Dr. around 10:15 a.m.
The suspects remain at large.
The vehicle was carrying between $4 million and $5 million dollars. No word yet on how much money is missing from the vehicle.
A spokesperson with ATM Solutions tells News 4 that none of the guards inside the vehicle were injured.
Investigators tell News 4 they are looking over a significant amount of surveillance video.
Caruso says that these suspects knew exactly what they were doing in this robbery. Whether or not this was an inside job is under investigation.