About 100 youths opened fire and wounded 16 French police in overnight clashes where gangs set cars, a leisure centre and a nursery school ablaze in the northern city of Amiens, a local government official said. \"Sixteen police were injured, some by buckshot fire,\" Thomas Lavielle, an official at the prefect\'s office in the region, told TELE TV station. Police reinforcements would be sent into the city in the coming hours, he was quoted as saying by Reuters. Local media said the clashes were apparently sparked by tension over spot police checks on residents in recent days.