Two local trains collided head-on in Denmark on Thursday, injuring at least 17 people, four of whom were in a critical condition, the emergency service said.Public broadcaster DR showed images of two yellow and grey trains, both with visible damage to the front, facing each other in a wooded area.The incident happened north of Copenhagen, on a train line linking the towns of Hillerød and Kagerup, police said in a statement. “It is two local trains that have collided head-on,” a...