Protesters and police clashed on Saturday morning in the western German city of Essen, the site of a two-day party congress by the Alternative for Germany (AfD) that is due to get under way. A large group of protesters attempted to break through a police cordon at around 5:45 am (0345 GMT), a police spokeswoman said. Officers used pepper spray and batons to stop their advance, she said. It was not immediately known whether there were any injuries among the demonstrators. Up to 100,000 protestors are expected to descend on Essen. The authorities have raised concerns that, while most of the expe…