Part of a football stadium in the Netherlands has collapsed trapping people under the wreckage.Part of the FC Twente football stadium caved in around midday, according to a police spokesman."People are trapped but we don't know how many," said Jan Lamberts.Emergency services are at the stadium in the city of Enschede, which was reportedly undergoing renovation work during the off season.Rescue workers are trying to free people trapped under the rubble.A medical helicopter is also at the scene to treat the injured, said Dutch news agency ANP.Pictures on local news websites show a large section of the roof has crashed on to a bank of red seats behind one of the goals.The team, Dutch national champion in 2010, was believed to be training elsewhere at the time of the collapse.