The British government will release an additional £46m in UK aid to the global fight against land mines, amid evidence that mine casualties, which had been declining, are rising once again.

The funding, the second tranche of an existing £100m commitment, was announced by the international development secretary, Penny Mordaunt, and is aimed at protecting an additional 820,000 people from the threat of land mines across Africa and Asia.

The programme will support the deployment of UK-funded technology, including radar detectors, designed to identify unexploded munitions in an area the equivalent of more than 16,000 football pitches. The devices used will include remote-controlled machines such as the the eight-tonne, Newcastle-built MineWolf, which can clear up to 12,000 square metres a day in the most high-risk environments.

The UK funding is also intended to support the training of all-female demining teams, in areas where many of the men have died in conflict.

The legacy of fear, mutilation and devastation that landmines leave must be wiped out Penny Mordaunt

Hundreds of women from impoverished communities are being empowered through skills training to perform landmine clearance, and to work as vehicle mechanics and paramedic first-aiders to protect their communities.

Announcing the new funding, Mordaunt said: “The crippling legacy of fear, mutilation and devastation, which landmines leave, must be wiped out for good.

“UK expertise and innovation are helping to shield vulnerable people from these barbaric relics and liberating land contaminated by these devices. This will allow the poorest people to grow crops, walk their children to school without fear and ultimately give them back control over their lives.”

British support will also help to educate a further 280,000 men, women and children about the dangers of land mines, an essential lifeline to safeguard communities from mutilation or death.

The global battle against land mines, which the late Princess Diana brought to public attention through her campaigning, has long been seen as an international success story. But gains in the battle against mines have been pushed back, not least by the semi-industrial production of homemade mines by groups like Isis in Syria and Iraq.

Among the nine countries to receive the additional funding will be Angola, where, more than 20 years ago, Princess Diana’s iconic walk through a landmine-littered field drew attention to the issue.

The funds will also help demining efforts in Laos where, more than 40 years since the Vietnam conflict ended, landmine casualty rates are among the highest in the world. South Sudan, where civil conflict has led to widespread contamination with mines and cluster bombs, will also benefit.

Noting the recent spike in land mine casualties Jane Cocking, chief executive of the Mines Advisory Group, said: “Global deaths and injuries from landmines have hit a 10-year high. Today, one person every hour is killed or injured by a landmine – and almost half are children.

“These new funds will help us to rid some of the world’s most conflict-affected countries of landmines, cluster munitions and other unexploded weapons at a crucial time, impacting the lives of hundreds of thousands of people.”

James Cowan, head of the Halo Trust, a demining charity with which the Mines Advisory Group will participate in the programme, said: “The Halo Trust was founded exactly 30 years ago to free the world from the scourge of landmines for good. Today’s announcement moves us closer to that day.

“Mine clearance is the very first step in creating stability, development and ultimately self-reliance for people whose lives continue to be blighted by conflicts long after they end. Thanks to British taxpayers, these people will now be able to live, learn and cultivate in safety.”

• This article was amended on 12 September 2018 to correct a misquote in briefing material supplied by the Department for International Development and the Mines Advisory Group