Turkey’s election officials have overturned the election of a pro-Kurdish mayoral candidate in the eastern city of Van, his party said on Tuesday, triggering protests and clashes with police as opposition politicians criticised the move. Police used tear gas and water cannon to break up a demonstration in Van, where the DEM party said its candidate inSunday’s municipal elections was ruled ineligible at the last minute. Demonstrations were also held in economic hub Istanbul. The ruling was “unacceptable”, Istanbul’s re-elected mayor Ekrem Imamoglu, seen as a likely presidential candidate in the…