<img class="styles__noscript__2rw2y" src="https://s.w-x.co/util/image/w/GettyImages-1153088976.jpg?v=at&w=485&h=273" srcset="https://s.w-x.co/util/image/w/GettyImages-1153088976.jpg?v=at&w=485&h=273 400w, https://s.w-x.co/util/image/w/GettyImages-1153088976.jpg?v=ap&w=980&h=551 800w" > An overall view shows smoke billowing up from of a forest on fire near the evacuated town of Alt Jabel in Mecklenburg-Western Pomerania, northern Germany, on July 1, 2019. (JENS BUTTNER/AFP/Getty Images)

At a Glance Unexploded bombs have made firefighting difficult in Germany and France.

Bombs exploded by a French wildfire date back to World War I, officials said.

Triple-digit heat has allowed wildfires to spread rapidly all over Europe.

As if the triple-digit heat isn't enough of a challenge for firefighters battling dozens of blazes across Europe, a pair of infernos in Germany and France have presented a new challenge: they've encroached on areas known to contain unexploded bombs.

One such fire is burning in the Mecklenburg-Western Pomerania state of northeastern Germany and has claimed more than 1.5 square miles of land , according to DW.com. Some 650 residents have been evacuated from three towns near the blaze, which has moved into a former military training site where many World War II-era bombs remain unexploded in the ground, the report added.

As a result, firefighters cannot get within a half-mile of the wildfire, and helicopters have been brought in to battle the flames.

"The situation remains tense," district official Stefan Sternberg told DW.com. "At the moment, the priority is not extinguishing the fire, but securing nearby villages and keeping people safe."

(MORE: European Heat Wave Shatters Records)

The fire, which was believed to be set on purpose, grew rapidly amid record-setting temperatures that soared as high as 103 degrees in northern Germany.

Meanwhile, about 100 miles east of Paris, crews struggled to put out a fire that had moved into a military training area in Suippes, France , according to Euronews. The area is peppered with bombs – several of which have exploded because of the wildfire – that date back to World War I battles in the Suippes forest, the report added.

"The fire is preventing the intervention operation to go further," Suippes mayor Jean-Raymond Egon told Euronews on Monday. "Shells have exploded since the fire started five days ago."

The cause of the fire, which has burned more than 1 square mile, is under investigation, according to local media.

July marks the month when crews comb the forest for unexploded bombs in an annual cleanup, the report added.

"Every year, between 5,000 and 6,000 unexploded shells turn up, and usually three-fourths of them date back to WWI", Egon told Euronews. "In this camp remain munitions aplenty."

In addition to the infernos in Germany and France, several large wildfires also continued to burn Monday in Spain.