International airline passengers arriving at British airports, including Heathrow Aiport near London, faced long lines at immigration checkpoints for several hours on Tuesday evening before the British Border Force announced that a nationwide computer outage that caused the delays had ended.
“Border Force is currently experiencing a nationwide issue which is impacting passengers being processed through the border,” Heathrow, the country’s largest airport, said on social media at 9:15 p.m.
Just before 2 a.m. on Wednesday, Heathrow announced that the issue had been resolved.
The Home Office, which administers the Border Force, said that it had fixed the outage across all airports shortly after midnight, according to BBC News.
A spokesman for the agency told the news outlet that the issue began around 7:50 p.m. Tuesday. There was no evidence of a malicious cyber attack and border security had not been compromised at any point, the agency added.
Manchester Airport, Gatwick Airport near London, Belfast International Airport in Northern Ireland and several other airports had reported being affected Tuesday evening, though the overall number of affected airports wasn’t clear.
Officials said that the problem originated with the Border Force’s “eGates,” immigration checkpoints that process arriving passengers through the border.
Officials at Gatwick and Manchester Airports said Tuesday that there were no flight delays or cancellations related to the outage, but said that they were working with Border Force officials to assist passengers experiencing delays at immigration.
Images on social media showed crammed, stagnant lines in front of a row of gates beneath signs that read “UK Border” at Heathrow Airport.