Vodafone has been inundated with complaints on social media from mobile customers struggling to make and receive calls on Tuesday afternoon.

Users started reporting problems shortly after 5pm, according to the Downdetector website. The problems are believed to have affected people across the country. The issue prevented voice calls connecting, but customers have still been able to text, use mobile data and make WhatsApp calls.

Responding to one customer on Twitter, Vodafone UK said: “We are aware that some customers may be experiencing issues with making outbound calls from their mobile, we have teams working to resolve this, sorry for any inconvenience.”

It is unclear how many people have been affected, though Vodafone has 18 million customers in the UK.

Customers have relied heavily on phone and internet access during the Covid-19 outbreak, which has forced people to isolate and work from home during the UK lockdown.

Vodafone said the problem was fixed shortly after 6pm at which point the network “started recovering”.

The company said the problem was caused by a change it had made to block a range of telephone numbers being used to make spam calls.

“We’d like to apologise to any customers who struggled to make phone calls this evening,” said a Vodafone spokesman. “We had an incident at around 17.20, which was fixed at 18.10. The service is now fully back to normal. Any customer struggling to make a call should quickly turn their phone off and on again to restart. We apologise for any inconvenience caused.”

Last month, millions of Virgin Media customers had problems accessing the internet during a series of outages across the country. The TV, broadband and mobile company, which has 5.3 million UK customers, said that the problem was not caused by its network being overloaded by high demand during the coronavirus lockdown.