General John Allen stepped down as the head of US and NATO troops in Afghanistan on Sunday and handed over the command to US Marine General Dunford. Dunford assumed command of the NATO-led International Security Assistance Forces (ISAF) at a ceremony in Kabul amid tight security, according to a report of DPA. "Today is not about change, it's about continuity," Dunford said. "I'll endeavour to continue the momentum of the campaign and support the people of Afghanistan as they seize the opportunity for a brighter future." The event was attended by senior Afghan and NATO officials including Defense Minister Bismillah Khan Mohammadi, German Army General Hans Lothar Domrose and General Martin Dempsey, chairman of the US joint chiefs of staff. Allen took command of ISAF in July 2011 from General David Petraeus.