Police are re-appealing for witnesses after a pensioner was injured and seven cars were damaged last month (Wednesday 25 May).
A reckless group of people are believed to have been throwing stones at taxis travelling along Bristol Road, Edgbaston out of the city.
The woman, who is in her 70s, was travelling along Bellevue Road at around 10pm when a stone smashed through a window of the taxi, hitting her on the head. She was taken to hospital where she was treated for a fractured skull.
A number of other cars were also damaged after the gang threw stones at passing taxis.
Police have vowed to take action following the attacks and have been granted an emergency order allowing officers to remove groups of people from the area who are thought to be involved in anti-social behaviour.
Officers investigating the crimes, including the assault on the woman, have looked at CCTV footage and are speaking to a number of people who have come forward with information.
Police patrols have also been stepped up to stop this happening again.
Detective Constable Chris Paintin from Force CID, said: “This incident is not an accident and clearly shows little regard for the safety of road users which is completely unacceptable.
“This woman was seriously injured and I would appeal to anyone who knows who is responsible to call me on 101.
“I would also appeal to those responsible to consider their actions and do the right thing and come forward so we can speak to you. It is only a matter of time before we come knocking at your door.”
Anyone with information is urged to call West Midlands Police on 101. Alternatively they can leave information anonymously by calling Crimestoppers the independent charity on 0800 555 111.