The Sri Lankan government on Wednesday expressed its outrage over the shooting of a political activist ahead of presidential elections later this month.
Several people were also wounded when unidentified gunmen sprayed bullets at the vehicle of supporters of former general Sarath Fonseka, the main opposition candidate in the poll.
The office of President Rajapakse, who is running for re-election, said the government was taking steps to catch the attackers.
"The government of Sri Lanka is appalled at this tragedy, vehemently condemns it, and will not tolerate any such acts of violence in the midst of this democratic electoral process," a statement said.
It said instructions have been given to authorities to bolster security at political events.
The government response came after the US embassy in Colombo said it was "deeply concerned" over the killing and escalating violence in the run-up to the January 26 election.
Fonseka quit the army and entered politics in November over differences with Rajapakse, who accused him of trying to seize power after crushing the separatist Tamil Tiger rebels.
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