LONDON (Reuters) -Exxon Mobil said on Wednesday it was isolating a unit at its Fawley oil refinery in Hampshire, southern England, following an incident that had led to gas flaring on Tuesday, adding that the site remains operational.

A spokesperson for the oil major said onsite teams were working on isolating the unit in question after it reported on Tuesday an “operational matter” at the plant.

The company did not provide any further details on the unit involved.