Singapore, Dec. 4 -- Two Indonesian soldiers were injured after a blast yesterday at the National Monument park, near the presidential palace in central Jakarta, police said.

A spokesman said President Joko Widodo was not in the palace at the time.

"Initial findings from our investigation... found that the explosion was caused by a smoke grenade," Jakarta police chief Gatot Eddy Pramono told a news conference, which was televised live.

"We are investigating. We did not find anything else after combing the area," he added.

Inspector-General Gatot said the two soldiers are being treated at an army hospital in Jakarta. One had hand injuries while the other had a leg injury.

Explaining the chronology of events, Jakarta military chief ...