Commuters were thrown into chaos this morning after Kings Cross station was evacuated during rush hour.

The major Tube station was closed just before 9am, forcing hundreds of passengers outside during the busiest time of the day.

TfL said the station closure was down to heavy overcrowding – however commuters said they saw "police everywhere", and said alerts in the station had described a "reported emergency". Disruption continued for nearly an hour, even though the station was reopened after about 20 minutes.

Nothing like closing #kingscross at rush hour to give me and a 3 and 6 yo a 1 hour jog across London! pic.twitter.com/tr3qMjY3YY — Liz O'hanlon (@teamnump) March 8, 2016

What’s going on at Kings Cross? People on the underground only allowed out of a single exit, and no one is allowed in. Police everywhere! — Lewis Painter (@LewwyPaints) March 8, 2016

The evacuation was affecting the Victoria, Circle, Metropolitan, Piccadilly, Hammersmith and City and Northern Lines.

Commuters were told to leave the platforms and ticket halls as the alarms sounded, and Twitter users posted pictures of the crowds as people spilled out of the station.

Definitely going to be late for my meeting, despite the early train! Kings Cross station completely evacuated pic.twitter.com/7Bb5eL1gk1 — Sophie Cliff (@sophiecliff) March 8, 2016

Kings Cross tube station closed at 9am on a weekday…madness pic.twitter.com/uJWnNchAmN — Philippa ??? (@Sketterss) March 8, 2016

https://twitter.com/ChloeMFisher/status/707130569549856768

Mass overcrowding at Euston as Kings Cross is closed pic.twitter.com/klP0Of1lAZ — Ed Fraser (@frasereC4) March 8, 2016

Something strange going on at Kings Cross. Station closed – Vic Line passed straight through. Trains from KGX delayed due to signals probs — David Calder (@davidcalder) March 8, 2016

Mass evacuation at Kings Cross St Pancras sirens going off etc. Does anyone know what's going on? I'm legging it… — karen childs (@westendlanegirl) March 8, 2016

Separately, mainline East Midlands trains from Bedford/Kettering into Kings Cross were being affected after a person was hit by a train today.

Network Rail teams and emergency services are currently on site and are working to re-open the service.

Three of the four lines were reopened by 2:30pm, but trains in both directions were suffering from a delay of up to 90 minutes, will be subject to short notice alternations and cancellations.

A normal service is not expected to resume until at least 6pm today.