Arsonists leave blazing trail through WA

Arsonists who lit eight fires as they travelled about 300km through three regions in Western Australia's south are being sought by police.

The fires were sparked along Albany Highway from Dwellingup in the Peel region to Cranbrook in the Great Southern region between 12.30pm and 4.15pm on Wednesday.

Police are seeking information from anyone who saw a vehicle on Albany Highway south of Cranbrook about 4pm and say a reward of up to $50,000 is being offered if the information leads to a conviction.