It's an uphill task and absence of peace with armed rebels means more mines may be laid in Colombia's vulnerable regions as international aid tries to de-mine areas affected by decades of conflict.

This month the United Nations and the Organization of American States pledged more funds to a seemingly never-ending operation that has absorbed resources that could have gone into Colombia's chronic poverty reduction programs.

OAS and U.N. representatives signed an agreement that hopes to push forward a now-on and now-off campaign to rid Colombia of tens of thousands of mines.

Colombian government negotiators seeking a permanent peace with the Revolutionary Armed Forces of Colombia, which is known by its Spanish initials FARC, armed rebels say at least 10,000 lives have been lost to exploding mines and thousands more of mostly rural Colombians have been maimed.

Land mines have forced more than 3.6 million Colombians off their land, the largest number of people displaced by mines after Sudan.

Officials blame FARC and other radical rebels for all the mines. Opponents of successive governments in Bogota say the state apparatus isn't blameless.

Campaigners for a mine-free Colombia want FARC to do all the de-mining, a demand unlikely to be met, partly because most rebel mining is unmapped, unlike documented minefields laid by government troops.

Signing the agreement, OAS General Coordinator for the Comprehensive Action against Antipersonnel Mines Carl Case and U.N. Mine Action Service Director Agnes Marcaillou expressed hope the deal would lead to greater engagement and coordination among various agencies involved.

Colombia has a Presidential Program for Integral Action against Antipersonnel Mines, a National Mine Action Authority and a cross-section of other agencies, citizens' groups and non-government organizations involved with clearing mines.

The OAS role in the effort is aimed at bringing order to the various, often disjointed, de-mining activities. The accord empowers OAS to oversee accreditation and assessment of de-mining operators, the quality of their work and post-de-mining inspection and recovery of areas cleared of mines.

Analysts say accidents leading to further injury or deaths can occur if an area is wrongly declared to be mine-free while it's not, so OAS needs to watch for quality assurance of all work undertaken by different groups. A greater sharing of expertise and information may improve matters, officials say.

U.N. Secretary-General Ban Ki-moon said eliminating the threat of mines and explosive remnants of war was a crucial endeavor that advances peace, enables development, supports nations in transition and saves lives.

"United Nations mine action programs continue to create space for humanitarian relief efforts, peace operations and development initiatives, allowing U.N. staff to deploy and refugees and internally displaced persons to return voluntarily to their homes," he said in a message to mark the International Day of Mine Awareness and Assistance in Mine Action.

U.N. aid is helping mine-clearing operations in about five dozen countries, including Afghanistan, Cambodia, Laos, Lebanon and South Sudan, contaminated by land mines. New threats have emerged with conflict in Mali and Syria, he warned.

From May 2011-May 2012, at least 4,286 people were killed or injured in incidents related to mines and explosive remnants of war, U.N. data indicated.

About 14 U.N. entities are involved with clearing mines.

Scottish mine clearing charity HALO Trust said that despite widespread mining of Colombian territory -- more than 10,000 areas identified as potential minefields -- "it is unlikely all of these still contain active mines."

Colombian Campaign to Ban Landmines said FARC rebels should take part in mine clearance operations, AlertNet reported.

"We're in the middle of peace talks and we believe it's a good opportunity and it's possible, for the government and FARC to reach a special agreement so that that the FARC can clear mines in some areas," campaign head Alvaro Jimenez told AlertNet in an interview.

Neither side has responded to the proposal, Jimenez said.