Millions of Virgin Media customers had problems accessing the internet during a series of outages across the country on Monday evening that the company said did not result from a network overload caused by high demand during lockdown.

The company, which has 5.3 million UK customers, ran into problems just before 5pm with customers complaining that their home internet connection was cutting out. Some also reported that their mobile internet connection was down.

The highest rates of reported outages were in cities including Birmingham, Bristol, Glasgow, Liverpool, London, Manchester, Nottingham and Southampton, according to data from website Downdetector, which recorded more than 30,000 reports.

Virgin Media said that the outages were not related to the capacity of its cable network, which offers customers broadband speeds of up to a gigabit per second in some areas, or heavy usage due to millions of Britons stuck at home turning to internet services to pass the time.

The company said the issue was not an “ongoing outage”, with broadband connections dropping for about three minutes each hour between 5pm and 7.30pm. It said the connection situation had improved by 7.30pm, although Downdetector continued to register complaints until at least midnight.

“An intermittent broadband issue that started yesterday evening was fixed in the early hours of Tuesday,” said a spokesman for Virgin Media. “This was not caused by increased usage or a lack of capacity. We know how frustrating this was for customers and we sincerely apologise for any inconvenience caused.

•This article was amended on 28 April 2020 to add an updated statement from Virgin Media