LONDON (AP) — British Airways says it has resolved a problem with its check-in systems that led to long delays and frustrated passengers at London's Heathrow and other airports.

The airline says the glitch caused "some delays for our customers" on Tuesday morning. BA says it had to use a manual check-in process that takes longer than the computerized system.

Problems were reported at U.K. airports including Heathrow, Gatwick and London City.

It says travelers are now able to check in normally, "and our staff are working flat out to help customers get away on their holidays."

It is the latest in a string of problems to hit BA, which suffered a huge global IT failure in May that grounded flights around the world.