SAN DIEGO (CNS) - Terror attacks at the international airport and a subway station in Brussels, Belgium that left at least 34 people dead and many more injured Tuesday also prompted San Diego area transit authorities to advise security personnel and passengers to remain vigilant.

Authorities at the San Diego International Airport have heightened security in light of the attacks, for which ISIS has claimed responsibility.
Passengers were also urged to report anything suspicious, airport spokesman Jonathan Heller said.

RELATED: Check San Diego International Airport flight status

''As always, passengers should always be aware of their surroundings and if they see anything that they think is unusual or suspicious, they ought to
tell security or police as soon as possible,'' Heller said.

"We are operating on heightened security status at SAN this morning due to the incidents in Brussels. This includes increased Harbor Police presence in the terminals. For more information, please contact Harbor Police," Heller said.

Metropolitan Transit System spokesman Rob Schupp told City News Service the agency issued a memo to security supervisors Tuesday morning alerting them to the situation in Brussels. It included a reminder for security personnel to keep an eye out for anything suspicious and to not hesitate to report
suspicious activity.

''All of our guys will be even more watchful today,'' Schupp said. ''They'll be taking notice of anything that looks suspicious.''

No service interruptions are expected in light of the attacks and travelers will likely not be affected by ramped up security efforts, according to Schupp.

However, passengers may notice a regularly deployed contingent of bomb sniffing dogs patrolling around transit stops -- especially those with high volume.

''They'll make their presence known today,'' he said.

San Diego Police Department Chief Zimmerman’s Public Safety Statement Regarding Belgium Attacks:

Our hearts and prayers are with the victims and families in Belgium today. Although there are no credible threats in San Diego, local law enforcement is closely monitoring the situation, coordinating with state and federal authorities, and taking all necessary precautions. We will not hesitate to adjust security measures to ensure the continued safety of our citizens. We ask everyone to remain vigilant and if you see something, hear something, or know something, please say something.