Ein Minenwarnschild auf einem nebligen Hügel.

In Kosovo, a small wooden marker stands at the side of a village road, the only memorial to a teenage cyclist who struck a cluster bomb and died - one of many forgotten victims of long-gone wars whose munitions are lying in wait to kill new generations.

And in Laos, the country most intensely hit by cluster bombs, the government estimates that up to a quarter of all villages are contaminated from munitions dropped by the United States half a century ago.

This week in Laos, countries that have signed on to an international convention to ban cluster munitions are gathering for the first time, four months after the treaty came into force, to review progress and bolster the campaign for universal endorsement.

Advocates are urging them to make sure it is ratified by parliaments worldwide, as well as to close loopholes that still allow the transit of cluster bombs, and economic assistance for countries producing or shipping the prohibited weapons.

Children are especially vulnerable to cluster bombs, or "bomblets" which sometimes resemble colorful playthings. And their small size makes it easy for them to nestle in shrubbery or long grass unseen. The bomblets are dispersed over wide areas from munitions dropped by planes, with the aim of decimating army units or guerrilla groups. Many fail to explode, and continue killing civilians for decades to come.

"Countries that support the ban need to interpret it and carry it out in a comprehensive way to end the humanitarian harm caused by cluster munitions," says Bonnie Docherty, senior arms researcher at Human Rights Watch. "This means explicitly prohibiting assistance to other countries with activities banned by the convention."

Canada, which spearheaded an anti-personnel mine treaty more than a decade ago, has signed the convention. But although it does not use or manufacture the weapons, it has yet to ratify it. Canadian advocates have asked Ottawa to introduce legislation that makes sure no funds are provided for the production or purchase of cluster bombs.

"While we are pleased Canada is attending this historic conference, we're very disappointed (it is) not doing so as a full state party," said Paul Hannon, executive director of Mines Action Canada, who is attending the meeting in Laos. "It was one of the first countries in the world to sign the convention, but now two years later, Canada still has not ratified it."

And he added, "we do not understand the delay. We know all parties support it. With all-party support we think Canada is in a position to have the 'gold standard' of national legislation compared to other countries."

Currently, 108 countries have signed the convention, 38 of them former users, producers, exporters or stockpilers of the weapons. Forty-two have ratified the convention and 10 have enacted the legislation that puts it into force.

But Russia, China and the U.S. are still outliers, and will be under pressure to join in as the meeting goes on.

They will hear from countries where the deadly effect of cluster bombs continues, even while international efforts are made to clear them away. Thirty-six countries are known to be affected by cluster munitions, from Afghanistan to Zambia, causing thousands of casualties. Meanwhile, 85 countries have stockpiled them.

On Tuesday, the International Committee of the Red Cross said that more than 800 million cluster bomblets are scattered over the Laotian countryside, causing an average of 300 casualties a year.