The March 1 assault by Taliban fighters against the generally perceived secured major military base in Helmand, Afghanistan, will result in some of the first combat action ribbons for a small group of Marines, whose primary task is advising Afghan forces.

Some of the Marines assigned to the small adviser group, known as Task Force Southwest, aided Afghan forces in repelling the attack on the vitally important Camp Bastion base, which according to the New York Times was stormed by Taliban fighters hiding in sewage tankers and by some militants who used ladders to scale walls and cross turf guarded by dozy patrollers.

The New York Times also reported that Taliban fighters had spies on the base, an Afghan lieutenant colonel and a sergeant major, who helped the militants hide.

The brazen assault by the outnumbered Taliban fighters calls into question the state of disrepair and security of the one of the most important Afghan military bases, which at the height of the war housed thousands of Marines and British troops and served as a focal point for America’s strategy to secure the volatile Helmand province.

A U.S. military official with Resolute Support said the U.S. side of the base was never under any real threat and that the American compound had its security perimeter. More than 20 Afghan forces were killed in the attack, which ended after hours of fighting with the aid of U.S. air support.

But following the breach, the New York Times reported citing American and Afghan officials, Taliban fighters took Afghan troops hostage, forcing them to guide the militants toward the command center where American troops were working.

According to the Times, previous Marine rotations had warned that the Regional Training Center on the base was susceptible to attack.

It’s not the first time Camp Bastion, now known as Camp Shorab, has been breached. But, it is the first major attempt on the military installation since U.S. forces handed control of the base to Afghan forces.

In 2012, Taliban forces stormed Camp Bastion and hit the flight line housing Marine Harrier jets. Six harriers were destroyed in the attack.

Lt. Col. Christopher Raible, the then-commander of Marine Fighter Attack Squadron 211, armed with a pistol spearhead a counter attack against the Taliban infiltrators.

Raible and Marine Sgt. Bradley Atwell were killed in the attack. Raible posthumously was awarded the Silver Star for his heroic actions during the assault on the base.

Corruption and poor leadership by Afghan commanders has dogged Afghan forces at the large Helmand base for several years.

A fourth rotation to Afghanistan by Task Force Southwest is currently on deck to deploy to the war-torn region.