Authorities have restricted traffic in Volos and the nearby mountainous area of Pelion where the storm has caused extensive power cuts.

Satellite images highlight the extent of the destruction in the area, with swathes of forest virtually flattened and lush pine trees turned into blackened, skeletal bark.

Firefighters say they are investigating whether the bodies, found near a shack south of the village of Avantas, were migrants.

The blazes, fanned by rising temperatures and strong winds, have killed five people, destroyed homes, farms and factories and scorched swathes of forest land since July 17.

The Civil Protection authority warned the threat of further blazes was high in almost every part of Greece, which is in the grip of a record-breaking heatwave that has also seen archaeological sites close.

Pakistani authorities say they arrested 14 suspects in connection with the alleged trafficking of migrants and police say they are searching for other suspects.

The protests were accompanied by a 24-hour strike – the biggest yet since the disaster – this time called by Greece's leading private as well as public sector unions.

Many of the people aboard an intercity passenger train that collided with a freight train were university students heading to the northern city of Thessaloniki from Athens after a long public holiday weekend.

The train, travelling from Athens to the northern city of Thessaloniki, was packed with university students returning after a long holiday weekend.

Police clashed with some of the demonstrators at a handful of protests, as public anger grew over the role that government mismanagement played in the tragedy.

Carriages were thrown off the tracks, crushed and engulfed in flames when a high-speed passenger train with more than 350 people on board collided head-on with a freight train.

The impact caused a fire in a number of the passenger carriages, burning many commuters who were rushed to hospitals.