(CNN)The ISIS-K suicide bomber who carried out a terrorist attack at Kabul international airport in late August, killing 13 US service members and dozens of Afghans, had been released from a prison near Kabul just days earlier when the Taliban took control of the area, according to three US officials.

Two US officials, as well as Rep. Ken Calvert, a California Republican who said he had been briefed by national security officials, said the suicide bomber was released from the Parwan prison at Bagram air base. The US controlled the base until it abandoned Bagram in early July. It had turned over the prison to Afghan authorities in 2013.

The revelation underscores the chaos around the final days of the withdrawal from Afghanistan and the struggle of the US to control a rapidly deteriorating situation around the airport as it relied on the Taliban to secure the perimeter of the airport.

The Parwan prison at Bagram, along with the Pul-e-Charkhi prison near Kabul, housed several hundred members of ISIS-K, as well as thousands of other prisoners when the Taliban took control of both facilities hours before taking over the capital with barely a shot fired in mid-August, a regional counter-terrorism source told CNN at the time. The Taliban emptied out both prisons, releasing their own members who had been imprisoned but also members of ISIS-K, which is the terror group’s affiliate in Afghanistan.

Eleven days later, on August 26, it was one of those prisoners who carried out the suicide bombing at Abbey Gate, killing the 13 US service members, including 11 Marines, one soldier and one sailor. They would be the last US troops killed in Afghanistan as part of America’s longest war.

As of Tuesday, one Marine injured in the attack remains in a serious but stable condition at Walter Reed Military Medical Center near Washington, the Marine Corps said in a statement. Another Marine is receiving care at a specialty facility, while 16 others are receiving outpatient treatment.

Two US officials confirmed attacker’s identity

ISIS-K took credit for the attack and named the suicide bomber as Abdul Rehman Al-Loghri. Two US officials confirmed the identity of the attacker. FirstPost, an English-language news site based in India, was first to report that he had been released from the Bagram prison.

The rapid transition from released prisoner to suicide bomber highlights the dangers Afghanistan could pose without a US military presence on the ground to monitor the latest developments in the country. Joint Chiefs Chairman Gen. Mark Milley said the threat from Afghanistan is currently lower than it was after the 9/11 attack, but he warned that conditions “could be set” for a reconstitution of al Qaeda or ISIS-K.