The New York Police Department ( NYPD) has beefed up security around landmarks in New York City in the aftermath of two explosions near the finish line of the Boston Marathon.

NYPD Deputy Police Commissioner Paul Browne told local media that the city is stepping up security at hotels and other prominent locations through deployment of the NYPD's critical response vehicles.

Browne added that the additional security will remain until more is learned about the explosions.

The MTA also announced its police department will conduct additional patrols and bag inspections in the wake of the Boston explosions.

The transit agency released the following statement:

"All security personnel will remind all employees to be vigilant. The increased coverage will continue until we fully understand the cause of the explosions in Boston. NYPD is also on alert and indicated they will give additional attention to the subway system."

Boston Police said at least two people have been killed and 28 people were injured in the explosions. The explosions went off within seconds of each other about three hours after the race began, according to officials.

So far, it is unclear what caused the explosions and no group has claimed responsibility.