The number of alleged sexual assaults committed by taxi or private hire drivers in Essex has doubled in the last three years, new data has revealed.

According to the figures obtained by the Guardian under freedom of information laws, 12 assaults were reported to Essex Police between April 2016 and March 2017.

This is an increase from six reports made in 2014 to 2015.

Nationally, at least 337 assaults were reported in the same period in England and Wales – up from 282 in 2014-15. A number of incidents were recorded where the victim was a child under 16.

The figures, obtained from 23 of 43 police forces across the country, relate to a wide range of vehicles, including illegal minicabs, Uber cars and black cabs. Most of the police forces could not break it down by firm or type of vehicle.

The disclosure follows a decision by Transport for London (TfL) to strip Uber of its operating licence in London, in part due to concerns about the company’s failure to report sexual assaults to police.

The company is appealing against TfL’s decision and its drivers can continue to operate while the appeal runs its course.

A spokesman for Essex Police said: “There is no greater priority for us than protecting people in our county from harm and the vast majority of licensed taxi drivers in Essex provide a safe and secure service.

“We take all reports of sexual offences seriously and we investigate them robustly. It is important to state these figures remain very low. We think it also shows that people are more confident about coming forward to report this type of crime to us and have confidence in us to investigate.

“We encourage anyone who has been assaulted, or has any information about an assault, to contact us.

“We work closely with local authorities with licensing and will continue to do so.”

Transport campaigners have stressed the importance of using licensed vehicles when travelling anywhere.

Southend councillor Tony Cox, who is actively working to firm up licensing rules surrounding Uber operating in the borough, said vigilance is key.

He added: “I would also say to anyone to use a licensed vehicle and would add that it should be one that is licensed locally as if there are any issues, the complaints can be taken forward here. If they are not, we are helpless to deal with it.”