ZAGREB, Croatia (AP) — Emergency officials say a forest fire that has spread to southern Croatia from neighboring Montenegro has triggered 34 explosions, probably from mines left over from the region's war in the 1990s.

The area near the walled Adriatic city of Dubrovnik was a frontline during the conflict that erupted after Croatia declared independence in 1991. Yugoslav army troops bombed Dubrovnik, a UNESCO heritage site.

Firefighter Mario Magud said Sunday the explosions were recorded between midnight and morning. Magud says the area of the fire is hard to access and was thought to be mine-free.

Both Croatia and Montenegro have been battling wildfires along the Adriatic coast amid extremely high temperatures and dry weather during the top tourism season.

Thousands of acres of pine forests and shrubbery have been burnt.