Military intelligence sources believe Russia is deploying anti-personnel mines along its defensive lines in the Donbas region of Ukraine.
The latest assessment from Britain's Ministry of Defence suggests the devices being used are "deeply controversial, indiscriminate weapons".
It says they have the potential to inflict widespread casualties.
Advertisement
Meanwhile, two more ships carrying grain have sailed from Ukraine's Black Sea ports, as part of a deal with Russia to resume some exports.
The vessels are transporting soybeans to Italy, and corn to southern Turkey.
Four ships which left yesterday are expected to have their cargo inspected near Istanbul later, as part of the agreement, before continuing on their journeys.
