A radar issue is causing disruptions to flights in the UK, limiting operations at two of Britain's busiest airports amid a record-breaking heat wave.

The UK's main air navigation service said it was dealing with a technical problem with a system at an air traffic control center in Swanwick, southern England, which was causing the flight restrictions.

"We are doing all we can to fix it as soon as possible," National Air Traffic Services (NATS) said in a statement Friday.

Heathrow and Gatwick, the UK's first and second busiest airports, respectively, both confirmed to CNN they had been experiencing limitations to their operations due to the air traffic control problem.

"Flights continue to arrive and depart from Gatwick however NATS -- which controls UK airspace -- currently has an issue with one of its radars and has put limits on the number of flights that can use Gatwick and other London airports," Gatwick Airport said in a statement.

Heathrow, which saw a record-breaking 37.9 Celsius (100 degrees Fahrenheit) yesterday, said: "Flights are currently arriving and departing at Heathrow, and we are supporting NATS to resolve the issue as quickly as possible. We apologise to passengers for any disruption that occurs as a result."

Stansted and Luton airports said their services were unaffected.

Flights are not the only mode of transport that's been interrupted this week in the UK. Rail services also suffered extensive delays due to the heat wave, which sent temperatures soaring to a record-high for July Thursday.

The owner of most of Britain's railway network warned that train tracks could buckle under the extreme heat, as the steel tracks were expected to exceed 50 Celsius (122 degrees Fahrenheit) in and around London.

Britain's railway tracks are able to cope with up to 27 Celsius (80 degrees Fahrenheit), the average summer rail temperature in the UK.