An explosion on Tuesday hit Indonesia's National Monument park, near the presidential palace in central Jakarta, leaving two military officers injured, local media reported, citing the police.

"We immediately secured the area," Jakarta Police Chief Inspector Gen. Gatot Eddy Pramono said at a press conference, adding that the blast occurred at the northern side of the park.

The victims have been sent to the hospital. Roadblocks were set up to check commuters and traffic in the area.

An investigation was launched following the explosion which was heard at about 8.30 a.m. local time, according to reports.