Deadly terror attacks at an airport and subway station in Brussels this morning have prompted officials to increase security at Union Station, Metrolinx spokesperson Anne Marie Aikins says.

Speaking to CP24 Tuesday morning, Aikins said customers should not be alarmed by the heavier than usual police presence.

“We haven’t had an increase in our terror alert… however, Union Station is one of our biggest transportation hubs in the country and there will be an increase in police presence there,” she said.

"We’ll be very vigilant, as we always are, but I want to alert customers that they will see an increase in police presence there, not to be alarmed by it but because safety is always our first priority.”

She said she does not expect the increased security will have an impact on service.

“We are taking this moment to moment. Situations can rapidly change so we are just very vigilant and (customers) should pay very close attention to the announcements and be very vigilant as well. We depend on our customers to be the eyes and ears of the system,” she added.

In a statement issued Tuesday, the TTC also asked its customers to keep an eye out for anything suspicious.

“The TTC and its staff remain vigilant at all times. We take our lead from law enforcement agencies, but ask our customers that if they see or hear anything suspicious, to report it to a TTC employee or police: see something, say something,” the statement read.

Toronto police Const. Victor Kwong said the Toronto Police Service has a “heightened awareness service-wide.”

“Although we do not discuss our operational plans, we can advise that we are monitoring and constantly re-assessing the situation and intelligence gathered,” he told CP24 Tuesday morning.

The Greater Toronto Airports Authority says it is also monitoring the situation.

"Whenever anything happens in airport community, we feel it. Our thoughts are with victims’ families and our colleagues at the airport," the GTAA said in a written statement.

"Will continue to work with CATSA, Peel and Transport Canada to make sure our passengers are safe. Brussels airport has issued a statement that notes that all flights in and out of Brussels have been cancelled today."