The National Crime Agency says they are seeing increases in the "scale and scope of the threat" from county lines.

County lines is where urban drug gangs expand their markets for crack cocaine and heroin into smaller towns.

They often exploit teenagers as drug runners and vulnerable addicts to provide flats to deal from - a process called cuckooing.

BBC News heard from an officer who said he didn't arrest for class A drug possession in order to safeguard vulnerable children faster.

Watch in full: County lines and the children they exploit