The US Pentagon has said there has been an explosion outside Kabul airport in Afghanistan as evacuations continue.
It's not known whether anybody has been hurt.
Earlier, the armed forces minister warned a terror attack at the site was "imminent" and "lethal".
Sky's Deborah Haynes is following developments:
"Details are very thin at the moment, we're waiting for more. I spoke to a British defence source who said that they were aware of reports of this explosion and and possibly gunfire."