People aged between 45 and 49 have become the latest to be offered the coronavirus vaccine.

An online booking system opened on Tuesday to allow people in this age group to book for their first jab.

The bookings begin the second phase of the government's vaccination programme.

The NHS has previously focused on offering vaccines to those considered to most vulnerable to coronavirus – those aged over 50 and people deemed be “clinically extremely vulnerable”, as well as health and social care workers.

However, there were some teething troubles on Tuesday morning after the website for booking Covid-19 vaccine appointments appeared to temporarily crash.

Some visitors to the site on Tuesday morning were faced with the message: “The NHS website is currently experiencing technical difficulties.

“We are working to resolve these issues. Thank you for your patience.”

Other users reported being placed in a queue, with a holding screen which read: “You are in a queue. Lots of people trying to book an appointment.”

Shortly after the vaccine booking site was hit by the technical issues, vaccines minister Nadhim Zahawi tweeted that the problem had been fixed.

According to the government, in total almost 40million doses of the Pfizer and Oxford-AstraZeneca vaccines have been delivered since their rollout began in the UK in December.

That includes 32m first jabs and more than 7m second doses.