Around 400 people have marched from link to RAF Waddington against a new fleet of armed drones being based in the UK for the first time.
The drones, which were previously operated from a United States Air Force base in Nevada, are used to support ground troops in Afghanistan.
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"Leah hasn't been seen since Saturday so of course we're all concerned for her safety and welfare."
Another fine day is expected on Tuesday after a frosty start. Plenty of sunshine but still rather chilly. Perhaps one or two light showers.
Starting frosty but gradually becoming less cold, with a northerly breeze. Becoming cloudy at times, with sleet and later rain showers.