Attackers have thrown a grenade into the compound of truce monitors in Sri Lanka's violence-scarred east, damaging vehicles and a building but causing no injuries, officials say. The attack came early on Saturday just hours after the Sri Lanka Monitoring Mission (SLMM) reprimanded both Liberation Tigers of Tamil Eelam separatists and the government over a spike in violence. It was the first attack against the monitors since a 2002 ceasefire halted a two-decade civil war.The bomb ripped through a car belonging to Scandinavian truce monitors, but there were no casualties, police said. The pickup truck of the Norwegian-led Sri Lanka Monitoring Mission (SLMM) was parked in their own premises in the town of Batticaloa, 300km east of Colombo, when the bomb went off, police said.