In January 1997, Princess Diana walked through a minefield in Angola and brought the problem of landmines to the world's attention.

Mozambique is one of 25 African countries still contaminated

Her actions angered some who felt she was making a political statement but, less than a year later, shortly after Diana's death, Britain joined more than 120 countries in signing up to the Ottawa Treaty.

A decade on, campaigners describe the treaty as a "success in progress".

A total of 80% of the world's countries have now pledged not to produce, use or stockpile landmines. The global trade in the weapons has virtually ceased.

Just two governments - Burma and Russia - are known to have used landmines last year. More than 40 million landmines have been destroyed since 1997 and thousands of square miles of contaminated land has been cleared.

"I think it's been an incredible success," said Simon Conway, director of the campaign group Landmine Action.

"You've got 155 states signed up to the treaty and the behaviour of a lot of other states that haven't signed up to the treaty is determined by it.

"The main thing it has achieved is that it has stigmatised a weapon. It is now morally impossible or unacceptable for most countries to use landmines."

Treated as outcasts

But despite these successes, many challenges still remain.

Although the number of people killed and injured by mines dropped by 16% last year, funding for survivor assistance programmes in many countries is inadequate.

Princess Diana brought the problem to the world's attention in 1997

As well as overcoming the physical and psychological trauma of their injuries, many landmine survivors are treated as outcasts in their own communities and struggle to gain social acceptance or meaningful employment.

Campaigners say too many countries are acting too slowly in meeting their obligations under the Ottawa Treaty to clear all mines under their jurisdiction and destroy their stockpiles within a set timescale.

Major powers such as the United States, China, India, Pakistan and Russia remain outside the treaty.

"Until they join, this gives the message that it's okay to use anti-personnel landmines and in some sense legitimises it for others," said Peter Herby from the International Committee of the Red Cross (ICRC).

The effectiveness of the Ottawa Treaty has encouraged campaigners to turn their attention to other weapons, which they believe should also be subject to a ban.

Campaigners want to extend the ban to munitions like cluster bombs

"Landmines are only one type of weapon that go on killing after conflicts," said Philip Spoerri, the ICRC's director for international law.

"The human cost of cluster munitions in particular, which are notoriously inaccurate and unreliable weapons, is an issue of pressing concern that requires urgent international action."

Representatives from dozens of countries and NGOs are meeting in Vienna this week in the latest stage of the "Oslo Process", which aims to bring about a ban on cluster bombs by next year.

There is no doubt the Ottawa Treaty has been a remarkable success. But activists are calling for continued effort to help the millions of people whose lives will continue to be blighted by landmines for decades to come.

"We cannot afford to rest yet," said Sylvie Brigot, executive director of the International Campaign to Ban Landmines.

"Sustained political leadership, financial and technical cooperation and assistance, and full and timely compliance with the treaty are crucial to ensure that the treaty can truly make a difference in the lives of all individuals and communities affected by mines."