Fire crews were called to a number of suspicious blazes within one hour yesterday evening.
Hemel Hempstead firefighters were called to an industrial wheelie bin that was well alight behind the Jubilee Pub in Queens Square, Adeyfield, at 9.30pm.
One hosereel jet was used to put out the fire. The cause of the fire was recorded as deliberate or doubtful, and police were informed. It was dealt with by 9.41pm.
Just eight minutes later, crews from Redbourn and St Albans received multiple calls about a suspected house fire close to the Ver Meadows caravan site near the Redbourn bypass.
The call turned out to be four separate fires in a field, which were again believed to be deliberate or doubtful.
One hosereel jet was used and the area was made safe by 10.17pm.