A burned road sign stands amid a burned landscape during a wildfire in the Rethymno region on the southern Greek island of Crete, Wednesday, where two firefighters died while battling the blaze. [AP]

Wildfires continued to burn across Greece on Friday, with firefighters battling overnight against strong winds and repeated flare-ups as authorities warned of a very high fire risk across much of the country.

The most serious blaze remained in the Agia Paraskevi area of Rethymno, on the southern island of Crete, where gale-force winds continued to hamper firefighting efforts. Ground crews worked through the night, while water-dropping aircraft resumed operations at first light. Authorities said protecting nearby communities remained the top priority as shifting winds repeatedly created new fire fronts.

New wildfires also broke out in Achaia, in the northwestern Peloponnese, and in the Xiromero area of Aetolia-Acarnania, a region in western Greece. Authorities issued an emergency 112 mobile phone alert to residents in the affected area of Achaia, while firefighters, supported by aircraft, were deployed to both blazes. Officials said weather conditions remained conducive to the rapid spread of the fires.