A suicide bombing outside the Abbey Gate at Kabul’s airport in Afghanistan Thursday injured at least three U.S. troops, U.S. officials confirmed.

A U.S. official indicated that the attack set off a firefight at Abbey Gate, where last night, there were 5,000 Afghans and potentially some Americans seeking access to the airport.

The bombing comes hours after the State Department warned Americans outside the gates of the Kabul airport to “leave immediately” due to the increasing terrorist threat.

LIVE UPDATES: EXPLOSION REPORTED OUTSIDE KABUL AIRPORT

A White House official told Fox News that President Biden has been briefed on the explosion. Biden was scheduled to meet with his national security team at 9:15 a.m. ET.

Secretary of State Antony Blinken said Wednesday there was a “very real possibility” of an attack.

This is a breaking news story. Check back for updates.