A new campaign has been launched by Birmingham City Council to raise awareness of the mistreatment and neglect of adults.
It is estimated that more than 5,500 older adults are abused in their own homes in Birmingham every year, the majority by family and friends.
However, only 560 cases were reported to the Birmingham Safeguarding Adults Board in 2009.
There are also adults under-65 with physical, sensory and learning disabilities or a mental health problem who are at risk of abuse. The bus poster campaign, launched on Tuesday, aims to raise awareness of the mistreatment of adults, older adults in particular, and how to report suspected abuse.
The Birmingham Safeguarding Adults Board, who are the organisers of the campaign, will also be displaying the posters across the city.
Pete Morgan, Birmingham City Council head of service for safeguarding adults, said: "Vulnerable adults need our care and protection.
"Last year, 560 older people living in their own home were referred to the Birmingham Safeguarding Adults Procedures, approximately one in 10 of the estimated total being abused.
"The city council, our health partners and the police are working to constantly improve reporting mechanisms, as well as raising awareness of the issue whenever possible."
If people suspect an older adult is being abused, they can contact 0121 303 1234.