Montreal police are on the hunt for a 25-year-old suspect after an armed robbery at Maisonneuve-Rosemont Hospital in the city's east end this morning.

A 59-year-old man is already in custody in connection with the robbery.

Police say the incident happened at 8:45 a.m.

Police Const. Caroline Chevrefils said the suspects approached a worker who was carrying money from the cafeteria.

Police said one of the suspects began yelling at the employee to give them the money. When security guards approached the men, one of the suspects pulled a gun.

"They had clearly been planning this," Chevrefils said. "They knew what time the money was being moved."

The suspects fled the scene on bicycles with an undisclosed amount of money.

Chevrefils said the older suspect was arrested a few blocks from the hospital.

Police said two hospital security guards and two other employees had to be treated for shock.