Calgary police are investigating three armed robberies that occurred in the city – within the last 24-hours.  

The first happened outside the TD Canada Trust bank in Crowfoot Centre in the northwest during a bank drop before six p.m. MT Friday night.  

The next took place around 9:30 p.m. MT at a northwest 7-Eleven in Hidden Valley. 

The third was at a Mac's convenience store along 52nd street N.E. around 4:30 a.m. MT this morning.  

Police say the first two robberies involved a gun and the last incident involved a knife.  

Investigators believe the robberies may be connected.

In all three cases, the suspects had a similar description: black male, wearing dark clothing, ranging in age from 18 to 30.  

Anyone with information is asked to call Crime Stoppers.