Afghan and foreign troops launched an operation to retake a southern Afghan town controlled by Taliban militants, officials said. The ground forces have surrounded the area and airstrikes are targeting militants inside Musa Qala, the town in southern province of Helmand, defense ministry spokesman Gen. Mohammad Zahir Azimi said. "The operation has started," said Maj. Charles Anthony, a spokesman for NATO's International Security Assistance Force. Taliban militants overran Musa Qala in February, four months after British troops left the town following a contentious peace agreement that handed over security responsibilities to Afghan elders. Musa Qala has been in control of Taliban fighters ever since.