A fugitive Germany Islamist has posted a third video in a week threatening to carry out attacks if people vote for Chancellor Angela Merkel in Sunday's elections.

Abu Talha, whose real name is thought to be Bakkay Harrach, also called on Germany to withdraw its troops from Afghanistan. The authorities say they are taking the threat seriously and will remain vigilant after the elections. Germany has so far never suffered an Islamist terror attack, though it has prevented several.

Police in Stuttgart arrested a German of Turkish origin on suspicion of uploading the video. He is not accused of taking the footage. It is not clear how the iamges came into his possession.