UNITED NATIONS, July 25 (Xinhua) -- UN Secretary-General Antonio Guterres expressed deep condolences to the relatives of the victims and the Greek government after wildfires killed over 80 people in the country.

Speaking through his spokesperson Stephane Dujarric, Guterres also commended the national response by the Greek authorities.

In addition, Dujarric said the UN's Office for the Coordination of Humanitarian Affairs is concerned with the raging wildfires in Greece.

"The United Nations stands ready to support the government and international efforts in responding to this disaster," he added.

On Monday afternoon, wildfires started in Mount Penteli on the Attica Peninsula of Greece, scorching seaside resorts and sending thousands fleeing.

By Wednesday, at least 80 people have lost their lives and 187 others are injured in the deadliest wildfire tragedy in over a decade.

Local mayors fear the number may exceed 100 soon as emergency crew continued to search thousands of scorched homes and cars.

Greece has been in national mourning since Tuesday.