Karl Peter Born, a German knifemaker, was heading to the beer stand at Solingen’s “festival of diversity” when the music cut out and an urgent voice addressed the crowd.

“There’s been a knife attack,” the voice announced over the sound system. “Leave calmly and keep your eyes open – they haven’t been caught yet.”

As Mr Born and his friends hurried home, the grim details began to emerge: a rejected Syrian asylum seeker had gone on a stabbing rampage that had left three people dead and eight others injured.

While shocking in terms of its brutality, this was hardly an isolated incident for Germany: it was one of five terrorist attacks committed by refugees in the run-up to this Sunday’s election.

The string of deadly attacks has handed an opportunity to the far-Right Alternative for Germany (AfD) party and led to one of the most rancorous election campaigns in decades, with asylum policy at the forefront of the debate.

Over the past 10 months, Germany has witnessed a knife attack in Mannheim that killed a police officer, a stabbing attack in Aschaffenburg that killed a toddler, and car-ramming attacks in the cities of Munich and Magdeburg.