KABUL, Afghanistan — U.S. special operations forces handed over their base in a strategic district of eastern Afghanistan to local Afghan special forces today, a senior U.S. commander said. The withdrawal satisfies a demand by Afghan President Hamid Karzai that U.S. forces leave the area after allegations that the Americans’ Afghan counterparts committed human rights abuses there on U.S. orders.

The transfer of authority ends a particularly rocky episode in the strained relations between the U.S. and Karzai. He had insisted that U.S. forces leave Nirkh district in Wardak Province over the alleged torture, kidnapping and summary execution of militant suspects there — charges U.S. officials firmly denied.

The incident shows the larger struggle of Karzai’s government to assert its authority over security matters, even as its green security forces try to assume control of much of the country from coalition forces on a rushed timeline, ahead of the scheduled withdrawal of most of coalition forces by December 2014.