Colombo  - An explosion triggered Wednesday on a rail track as a passenger train passed by the outskirts of Sri Lanka's capital injured at least 17 people, police said.

The explosion Wednesday morning occurred at Dehiwala, 10 kilometres south of the capital Colombo, after being triggered by remote control.

Police blamed Tamil rebels of the Liberation Tigers of Tamil Eelam (LTTE).

The explosion caused minor damage to the train compartment, but the train managed to pass by the blast and halt a few metres ahead. Some of those injured were traveling on the foot-board.

The incident comes less than 10 days after suspected Tamil rebels set off a bomb inside a train at Dehiwala killing nine passengers.

Government troops have intensified military operations against the rebels in the north and have called civilians to be alert about rebels trying to plant bombs in trains and buses. (dpa)