People can access the service by sending a text to 07786 200200

The system means people with hearing or speech impairments will not have to rely on others to report emergencies.

West Yorkshire Police said they can now have two-way text conversations with victims and witnesses to get the right information and respond appropriately.

The service can be accessed by sending a text message to 07786 200200.

Network delays

Officers have worked in partnership with Leeds City Council and the Leeds Society for Deaf and Blind people to develop the service.

It is solely for the use of deaf people and those with hearing or speech impairments.

Within about 20 seconds of sending an emergency message, users will receive a text acknowledgement followed later by a police response.

A police spokesman said the service cannot offer an instant response as mobile phone companies do not prioritise text messages.

"There may be a delay in a message reaching the police depending on the demands of the network," he said.

Anyone who does not receive a response to their text within two minutes is advised to try again or find another way of contacting 999.