An immense wave of outrage has sparked all across Germany, after the shooting of a petrol station clerk in a row over the wearing of face masks.

The clerk, a man aged 20, was shot and killed on Saturday by the customer, who became angry when asked to put on a face mask.

The man arrested in Germany did not have a firearms license, leading to calls for an investigation into how he obtained the weapon.

On Sunday, the customer, 49, walked into a police station to offer a confession. He told police he had acted “out of anger” after being asked to cover his nose and mouth.

The man was arrested on suspicion of murder.

Police in the city of Trier, 37 miles west of the town, said the suspect left the petrol station after the dispute but returned, wearing a mask, about an hour later. He drew a concealed revolver from his pocket, shot the clerk and fled.

“He further stated during interrogation that he rejected the measures against coronavirus,” they said.

Under German Covid restrictions, people are required to wear masks in indoor public spaces.

Germany’s chief public prosecutor, Kai Fuhrmann, said officers found the gun used in the attack, along with other weapons and ammunition, during a search of the suspect’s home.

He did not hold a gun licence and investigators are working to determine how he obtained the arms.

Mr Fuhrmann told the DPA news agency the victim had received a shot to the head.

The shooting, in the town of Idar-Oberstein, has prompted an outpouring of sympathy from politicians in Germany as millions of voters prepare to elect a new chancellor.

Annalena Baerbock, the Green candidate running in the election, expressed concern about the “radicalisation” of the pandemic sceptic movement.

“I am shocked by the terrible murder of a young man, who had only asked others to follow the prevalent rules, to be considerate and show solidarity,” she said on Twitter.

“I am greatly concerned about the radicalisation of the Querdenker [Germany’s movement of pandemic sceptics]. We all need to stand up to growing hatred.”

The mayor of Idar-Oberstein, Frank Fruehauf, expressed his shock and dismay at the crime.

“This is a quite inconceivable, terrible act that has happened here in Idar-Oberstein,” he said.

“Such a crime is unprecedented. It will take time to come to terms with it.”