By Ros Tappenden

Copyright bbc

Sgt Lyn Smith, of the force’s Joint Operations Marine Unit, said searches and patrols were being undertaken in the build-up to the visit.

“We have specialist equipment that we will be using and our officers are highly trained in search and patrol,” the officer said.

“We will be working alongside our partners the Environment Agency who will also be deploying onto the river, in order to maintain the safety of everyone.

“As well as the patrol and search activity, we will be engaging with those using the river and speaking to local businesses who operate cruises or other leisure activities on the water.”

The force has urged the public to remain vigilant and raise concerns with police or the Environment Agency by calling 101 – or 999 in an emergency.