LONDON — Dozens of flights have been delayed or diverted at London’s Gatwick Airport after its one runway was closed because of a suspected oil spill.

The airport said flights were suspended after a “spillage” on the runway at around 10:15 a.m. Monday. The runway reopened about 90 minutes later.

According to Gatwick’s website, at least 19 incoming flights were diverted to other London-area airports and there were delays for many departing flights as a result of the closure.

The airport did not say what substance had spilled, but media reports said oil had leaked from a jet upon landing at Gatwick, which is 30 miles (50 kilometres) south of London.