Four people were injured when an old aircraft bomb exploded at a bridge near the main train station in the German city of Munich on Wednesday, police said on Twitter.

The Munich fire brigade said one person was seriously injured.

Explosives experts were summoned to the site to examine the remains of the bomb, the fire brigade said.

The explosion took place during drilling work at a construction site, police said. The danger area has been cordoned off.

Rail travel to and from the station has been suspended due to the explosion, according to rail operator Deutsche Bahn. 

More than 2,000 tonnes of live bombs and munitions are discovered each year in Germany, more than 70 years after the end of World War II. During the war, British and American warplanes pummeled the country with 1.5 million tonnes of bombs that killed 600,000 people. Officials estimate that 15 percent of the bombs failed to explode, some of which were buried 6 meters deep in the ground.

(With input from Reuters)