A Sri Lankan opposition supporter was killed on Monday as fresh unrest erupted ahead of next week's presidential election despite a security crackdown, police said.
The man was killed in a clash with ruling party activists in northwestern Sri Lanka, marking the third politically-related death in the run-up to the presidential vote on January 26.
Supporters of the main opposition candidate, former army chief Sarath Fonseka, were attacked in the town of Wariyapola while they were putting up election posters, police said.
"One man was killed and several others sustained injuries," a spokesman for the police election secretariat said.
Police say they have reports of nearly 600 poll-related incidents of violence already.
President Mahinda Rajapakse, who is running for re-election, has ordered a security crackdown to quell unrest, his spokesman Chandrapala Liyanage said.
"The president is deeply concerned about the violence and has already ordered police to make sure that there is tighter security," Liyanage told AFP on Sunday.
"He is also appealing to all parties to ensure there is no violence."
Opposition activist Kusuma Kuruppuarachchi, 60, was the first to be killed in the poll campaign when she was shot in the southern town of Hungama last week.
Police also fired tear gas to disperse thousands of party workers in the eastern town of Polonnaruwa after mobs destroyed vehicles and buildings on Wednesday.
The US embassy in Colombo said it was concerned about the escalating violence in Sri Lanka, where the government last May crushed the separatist Tamil Tiger rebels last year and ended decades of ethnic war on the island.
"Those who lost their lives are not the only victims of these brutal attacks -- democracy is also a victim," the embassy said in a statement. "Such violence undermines the democratic rights and traditions of Sri Lanka."
The United States was recently accused by a ruling party legislator of funding the main opposition to oust Rajapakse. The allegations were denied by the embassy.
Opposition leader Ranil Wickremesinghe has accused Rajapakse's People's Alliance of inciting violence and using intimidation to swing voters.
Rajapakse is facing a tough challenge from Fonseka, who quit the army and entered politics in November.