MOBILE phone users on one of the world's largest providers have been experiencing signal problems due to a mixture of unexpected issues and network upgrades.

People using Vodafone in the Worcester area have had difficulty making and receiving calls since Friday, June 20 but the company says it is working to fix the problem that "might be affecting call coverage."

A message on their website added: "There are some challenging circumstances - so it's taking us longer than usual to get to the bottom of things."

Vodafone will also be doing some scheduled work to improve 2G and 3G call and data coverage between 8am and 8pm on Friday, June 27, and apologised to any users who notice any disruption.

The world's second largest mobile phone company confirmed it had already completed some planned work on the network in the area to improve the 2G and 3G call and data coverage between 8am and 8pm on Sunday, June 22.