Two candidates in Sunday's regional elections in Colombia have been killed, bringing the total of candidates killed during the campaign to at least 21.
Security has been tightened nationwide ahead of the polls
Gratiniano Murcia and Liliana Polania from the Citizen Convergence party were shot as they campaigned in the south-western province of Caqueta.
The government has blamed most of the deaths on guerrillas from the far-left Farc movement.
Some parties have withdrawn candidates due to the increasing violence.
The two murdered candidates were visiting the town of El Diamante on Tuesday when they were shot.
"Police urged them against going to that area," interior minister Carlos Holguin told local radio.
"There are still investigations underway, but we believe this is the Farc," he was quoted by the Reuters news agency as saying.
Government officials say 21 candidates have been killed, although other sources put the toll higher at 29.
President Alvaro Uribe announced last week a $25,000 (£12,200) reward for any information leading to the arrests of those responsible for the murders of candidates.
Colombians will vote on Sunday to fill some 15,000 regional posts, including governors, mayors, regional assembly members and municipal officials.