Travellers have set up home on a nature reserve in Kingswood.
The travellers have set up camp on an area called Wilberforce Wood, formerly known as Midmeredales.
The land is a designated dog walking area.
A Hull City Council spokesman said: "We are aware travellers have set up an illegal encampment.
"We are currently working with our multi-agency partners, following our procedures and will start legal proceedings as necessary.
"We will continue to monitor this area."
Any residents with concerns should report them via 01482 300 300.
