KABUL (REUTERS) - The commander of the Taleban's "special forces" branch, known as the "Red Unit", was killed last week in Helmand province by Afghan forces, according to Afghanistan's main intelligence agency.

The National Directorate of Security (NDS) said Mullah Shah Wali, also known as Mullah Naser, was killed in an air operation in Helmand.

The province is a Taleban stronghold in the heartland of Afghanistan's lucrative drug trade.

Wali became the commander of the Taleban's "Red Unit" as well as deputy shadow governor of Helmand province three years ago and was directly involved in Taleban offensives, the statement said.

The "Red Unit" is thought to be equipped with advanced weapons, including night vision scopes, 82mm rockets, heavy machine guns and U.S.-made assault rifles, according to the Afghan military.

Wali was killed alongside a suicide bomber and two other Taleban commanders in Helmand's Musa Qala district, according to the NDS.

The United States has worked hard to build up Afghan air support and attack capabilities since they were found inadequate after most foreign forces withdrew three years ago.