The Taliban have claimed victory after a days-long brutal battle in the Panjshir Valley, which was the last area of the country out of the militant group’s control. Taliban spokesman Zabihullah Mujahid issued a statement on Monday, claiming that thousands of fighters finally secured the region, which had been under the control of a group led by Ahmad Massoud, the U.K.-educated son of a legendary anti-Taliban fighter—but Massoud has not conceded defeat publicly and his whereabouts are unknown. “We tried our best to solve the problem through negotiations, and they rejected talks and then we had to send our forces to fight,” Mujahid told a press conference in Kabul. The valley—which is accessible only through a narrow mountain pass—has been historically difficult to claim, with local fighters keeping control against Soviets in the 1980s and against the Taliban when they first came to power more than 20 years ago. It is unclear how many fighters died in the current battle.