The raiders targeted the vehicles in a caravan park in Garstang.
Lancashire Police are appealing for any information after three caravans had their windows removed and stolen on Cockerham Road at around 6.50pm yesterday.
Two males were seen running from the caravan park just before police arrived down Croston Barn Lane. They made off in a dark coloured vehicle.
Anyone with information is asked to contact 101 quoting log LC-20190225-1254.