West Mercia Police believe the trend, targeting hay and straw stacks across northern England, may be linked to a TikTok challenge encouraging people to set fire to things in the countryside. Humberside Police are currently investigating six suspected arson attacks on hay bales. These incidents were reported overnight in North Lincolnshire on July 30. West Mercia Police said: "Following a recent spate of overnight arson attacks on hay stacks in the north of England there appears to be a TikTok challenge to 'set fire to as much stuff as possible.' "I know the farming community will be aware of the dangers of the dry weather but if it is possible to send out a message to all your members to be extra vigilant."