Halton Regional Police are investigating a robbery after a buy and sell transaction went south. A Seller posted an online ad for an IPhone and on Saturday night the seller met with an individual near Mitchell Place and Bowring Court in the Town of Milton. When the seller turned the cell phone over to the potential buyer for inspection, the suspect took off on foot before hopping into a nearby vehicle with the phone. The seller ran in pursuit until he noticed something that looked to be a firearm pointed in his direction. No injuries are being reported in the incident, The suspects are described as two black males, 18-22 years old that took off in a newer model black 4 door Mercedes Sedan. Police would like to remind the public to exercise caution when buying and selling items online and to always arrange for transactions to take place in well-lit, areas such as malls, coffee shops or the parking lot of any police station.