In the wake of today's explosions at the Boston Marathon, San Francisco Police Department is on heightened alert. SFist talked to SFPD spokesperson Albie Esparza, who told us that SFPD will be more vigilant today when it comes to critical infrastructure (e.g., tourist-heavy areas. public transportation, etc.).

Expect to see more uniformed officers around the city as well.

SFPD Chief Greg Suhr will make a formal address to the public at around 2 p.m. today at the Central Market Safety Hub at 72 Sixth Street, according to SF Appeal.

At least two people were killed, and dozens injured, when two bombs went off at around 2:50. This happened near the finish line where hundreds if spectators stood cheering on winners.

We'll update as soon as we know more. The cause of the explosions are still under investigation, but were reportedly from small portable bombing devices. Follow Gothamist here for breaking news updates.