The reason for the flight which crashed today at Southend Airport has been revealed. Witnesses said they saw a "huge fireball" and black smoke after the incident at around 4pm.

Emergency services including the police, fire service and ambulance service rushed to the scene - and two nearby sports clubs were closed as a precaution. It has now emerged that the plane that crashed was medical transport jet and a twin-engine Beechcraft King Air B200. It was travelling from Southern to Lelystad in the Netherlands, where its operator Seusch Aviation is based. The aircraft, operated by Zeusch Aviation, was equipped with medical systems for transporting patients. The Dutch company specialises in medical evacuation services and transplant flights. It also runs private charters.

It's not clear whether the flight being operated was a medical evacuation - or whether any patient was onboard at the time of the crash. The cause of the crash is not known yet.

David Burton-Sampson, MP for Southend West & Leigh, said on X: "I am aware of an incident at Southend Airport. Please keep away and allow the emergency services to do their work. My thoughts are with everyone involved."

Essex Police said in a statement: "We remain on the scene of a serious incident at Southend Airport. We were alerted shortly before 4pm to reports of a collision involving one 12-metre plane.

"We are working with all emergency services at the scene now and that work will be ongoing for several hours. We would please ask the public to avoid this area where possible while this work continues."

Essex County Fire and Rescue Service added: "We were called to an incident involving a light aircraft at Southend Airport today at 3.58pm. Crews from Southend (two), Rayleigh Weir and Basildon (two), along with off road vehicles from Billericay and Chelmsford attended.

"We are continuing to work at the scene with our emergency services and aviation partners. Please avoid the area if possible while this work continues."