KABUL, Feb. 20 (Xinhua) -- Up to 28 Taliban militants have been killed in southern restive province of Helmand, the Afghan Defense Ministry said Tuesday.

"Twenty-eight terrorists were killed as a result of cordon operations and airstrikes in Dishu, Garmser, Marja, and Musa Qala districts of Helmand," the ministry tweeted.

Four heroin factories and a control and command center of the enemies were also destroyed during the fresh operations and airstrikes, it said.

Helmand, notorious for poppy growing, is also a known Taliban stronghold.

The Taliban insurgent group, which has been waging an insurgency of more than 16 years, has yet to make comments.