A gunman has opened fire inside a tram in the Dutch city of Utrecht.

Several people have been injured and one is feared to have died in the shooting at about 10:45 local time (09:45 GMT) near the 24 Oktoberplein junctions, reports say.

Police say the gunman is still at large. Trains and trams have stopped running and schools have been asked to keep their doors closed.

Counter-terror police reportedly say it "appears to be a terrorist attack".

The Dutch anti-terrorism co-ordinator is in touch with local authorities and says the threat level has been temporarily raised to its highest point in Utrecht.

Heavily-armed police are reportedly gathered outside a house on a nearby street and keeping bystanders back, with reports they are preparing a raid.

Prime Minister Mark Rutte said he was "deeply concerned" and canceled his weekly coalition talks.

Security services have reportedly told Utrecht's University Medical Centre to open the dedicated emergency ward to help care for the injured.

Utrecht University has reportedly closed all buildings, with nobody allowed in or out. Trains are also not allowed to run into Utrecht Central station, and mosques across the city have reportedly been closed due to security concerns.

"A man started shooting wildly," one eyewitness told Dutch news site NU.nl.

Another witness told Dutch public broadcaster NOS he saw an injured woman with blood on her hands and clothes.

"I brought her into my car and helped her," he said. "When the police arrived, she was unconscious."

It is unknown how many were injured or how seriously they were hurt.

Utrecht's transport authority said some tram services were again running in the city, although warned travelers to "take into account additional travel time".