Croatian firefighters and armed forces were fighting dozens of wildfires on Monday along the Adriatic coastline and on the popular tourist islands of Hvar and Brac, officials said.
The situation was most severe in the mountains around the mainland city of Zadar, where 32 fires have broken out since late Sunday, according to Slavko Tucakovic, chief commander of Croatia's firefighters.
The authorities closed part of the highway linking the capital Zagreb with the second largest Croatian city of Split. Local media reported that some drivers, fearing the fire, turned their cars around and drove in the opposite direction.
A dozen jets and helicopters were trying to bring the fires under control, with some 100 soldiers along with firefighters from other regions sent to help. Strong winds were making the job more difficult, Tucakovic said.
"We have to... group our forces and move them from one settlement to another to defend houses as fire breaks out," Tucakovic told local media.
One fire threatened a suburban army barracks but was kept under control, he added.
Other blazes broke out near the coastal city Sibenik, where several people were reported to have been evacuated from a hamlet overnight Sunday.
The forest fire on Hvar could be seen from Split, local media reported, but there were no reports of towns or villages being in danger on the islands.
According to Tucakovic, the causes of the fires were a long drought and strong winds, but also the "irresponsibility of people who, intentionally or not, caused a number of fires".
Soaring temperatures and tinder-dry forest floors across southern Europe have led to a rash of devastating wild fires, notably in Portugal, where 64 people died in a massive inferno in June.
This summer's fires in Croatia are among the country's worst in several years, with 83,000 hectares (205,000) of forests damaged -- double the area burnt in 2012, Tucakovic said.
In neighbouring Bosnia, firefighters were on Monday struggling to defend three villages near the southern town of Mostar that were endangered by one of several active wildfires in the area. Army helicopters were unable to help owing to the strong winds.