India, July 6 -- Hundreds of firefighters battled wildfires in Portugal and Greece on Sunday, with Spain and Italy sending reinforcements to Portugal to help battle a massive blaze burning for more than three days.

In Greece, authorities on Sunday urged residents of parts of Thessaloniki, the second-largest Greek city, to remain indoors and shut their windows and doors due to toxic smoke from a burning recycling plant that was engulfed by a wildfire on the outskirts of the city. In central Portugal's Vouzela area, more than 1,200 firefighters backed up by nearly 400 vehicles and 15 aircraft tried to put out a blaze that broke out on Thursday, according to the country's Civil Protection authority. The wildfire had burned across an area of...