(CNN) -- At least 19 soldiers were killed over the weekend in separate clashes with rebels in Colombia, the country's president said.
President Juan Manuel Santos reported attacks by the Revolutionary Armed Forces of Colombia, commonly known as the FARC, in Arauca and Caqueta.
In the department of Arauca, which borders Venezuela, rebels ambushed a group of soldiers guarding an oil pipeline. Fifteen soldiers were killed and 12 rebels were captured, Santos said.
Another four soldiers were killed in Caqueta, which is a department in the south of the country.
"The instructions to our forces are as follows: Don't stop shooting, even for an instant until we reach the end of the conflict," the president said, according to his office.
Santos vowed operations will continue until those responsible are held to account.
The violence comes amid peace talks between the government and the FARC. The two sides have been at war since the 1960s.
Santos has said he wants talks, which started last year and are taking place in Cuba, wrapped up by November.
There have been sporadic attempts at peace in the past.
The last effort fell apart in 2002. Then-President Andres Pastrana ceded an area the size of Switzerland to the guerrilla group, but he ended negotiations after rebels launched a series of attacks across the country in an apparent bid to strengthen their position.