Firefighters from Sanquhar in Upper Nithsdale have been called out to the fires around the town.
They have managed to put them all out without serious damage but suspect it is the same person starting all of them.
Three fires were set off in and around Sanquhar within the space of four hours on Wednesday and then a fourth was discovered alongside the A76 Dumfries - Kilmarnock Road at Guildhall Bridge, Kirkconnel.
The latest was on Friday night at Mary’s Street at Sanquhar where firefighters managed to put out the flames using beaters.A Dumfries and Galloway Fire and Rescue spokesman said:
“The fires were all put out by the firefighters using beaters and hoses.“The causes of the fires have been put down as suspected to be deliberate by an unknown person or persons.”