The leader of Colombia's FARC rebels, known as Timoleon "Timochenko" Jimenez, has pledged to seek peace and bring an end to his group's half-century of armed struggle.

The latest peace overture, in a letter posted on the FARC website, came one week after Jimenez vowed to end kidnappings for ransom and to free the group's last 10 police and military captives.

Jimenez, whose real name is Rodrigo Londono Echeverri, said the Revolutionary Armed Forces of Colombia (FARC), Latin America's largest remaining guerrilla group, wants to end decades of armed struggle.

"We believe it's worth trying to break that cycle and begin working on reconciliation and peace," he said in the letter.

"It is unfortunate that every day blood is spilled of humble Colombians. No military or police should die. Neither should the guerrillas."

Colombian President Juan Manuel Santos says he will open a direct dialogue with the FARC only when all hostages are released and the group vows to cease "terrorist" actions. He also wants the FARC to stop recruiting children.

In the letter, addressed to Colombian peace activist Marleny Orjuela, Jimenez renewed his pledges to release the last police and military captives and to end kidnapping for ransom, as announced on February 26.

The FARC are also believed to be holding a large number of civilians. Jimenez said figures on civilian hostages -- one citizen group estimated the number at 405 -- were "false."

Pressure has been mounting on the group since three policemen and a soldier -- held for more than 12 years -- were allegedly executed on November 26 during a government assault on a rebel camp. The incident set off nationwide anti-FARC protests.

Santos broke off contacts with the FARC early last month after the group was blamed for two separate car bombs that left 15 people dead and 100 others wounded.

The FARC, believed to have 8,000 members, has been at war with the government since 1964. It began a campaign of kidnappings in the mid-1980s, seizing army hostages to serve as bargaining chips for FARC prisoners.

By the late 1990s, the group won greater notoriety by snatching civilians and political leaders.

Colombia's best-known hostage was former presidential candidate Ingrid Betancourt, a dual French-Colombian national who was kept in captivity in the jungle for six years.