North Yorkshire police are working with officers in North Wales to investigate a fresh nail bomb attack against a chip shop owner in Holywell.

Jonathan Davies, 34, narrowly escaped injury when a letter bomb, packed with nails, exploded in front of him and his customers.

The bomb was the latest in a series, including two in North Yorkshire, sent to homes and businesses. And an officer is travelling to North Wales today to assess whether this new incident is linked to the other four.

After a meeting at the beginning of the week, police confirmed that four letter bomb attacks across the north of England were linked.

North Yorkshire police joined forces with Humberside and Cheshire police forces to investigate attacks which appeared to be against the agricultural industry.

A spokeswoman for the force said: "North Yorkshire police are leading the inquiries into the nail bomb incidents. And when there is a similar incident in another part of the country we will work with their officers."

Last Friday a 58-year-old sheep farmer was injured by a nail bomb containing half-inch nails posted to his Ripon home. The incident followed one in nearby Masham when a similar device was sent to an agricultural firm.

The third incident left an office assistant with facial injuries after she opened a device in a padded envelope delivered to Frank Hill and Son estate agents in Market Place, Patrington, Hull.

And the fourth incident was on December 31, when the six-year-old daughter of the owner of a pest control company in Congleton, Cheshire, suffered leg and foot injuries when a letter bomb exploded.

Updated: 11:22 Friday, January 12, 2001