Colombo  - Security in passenger trains was intensified in Sri Lanka Wednesday after 24 people were injured in an explosion triggered on a railway line as a passenger train passed by the outskirts of the capital.

The explosion 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 travelling on the footboard.

The man who triggered the explosion was spotted by some of the bystanders, but he had managed to board a bus and escape. Initially no one had confronted him fearing he was a suicide bomber.

Security in the passenger trains have intensified with more checks on all passengers carrying parcels while in some of the trains armed army guards have been deployed.

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

On Monday night, six civilians travelling in a van in a rebel controlled area were killed in a claymore mine explosion. Rebels blamed the Sri Lanka army's deep penetration unit for the attack but the army denied this.

But, civilians in the south fear of reprisal attacks when there are reports about civilians being killed in the north. Rebels previously also have claimed that the army's deep penetration unit were engaged in attacks during which civilians have been killed.

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)