Harpenden and St Albans rail users are facing disruption on the Thameslink service thanks to a trespasser on the line.

Thameslink has tweeted: “All lines blocked at Harpenden due to a trespasser on the railway.

“Services in the area are being held & will be subject to disruption.”

The rail operator has warned that disruption is expected until 6pm.

Thameslink states online: “A trespass incident at Harpenden means that trains between London St Pancras International and Luton are being delayed whilst emergency services attend the issue.”

Arriva buses are accepting tickets from St Albans City station to Hatfield station on routes 300, 301 and 724, according to Thameslink.