Updated

A Syria monitoring group says a convoy of Islamic State militants and their relatives transferred from the border with Lebanon has finally crossed into an extremist stronghold in eastern Syria, ending a standoff with the U.S.-led coalition over their evacuation deal.

The convoy had been stuck in the desert following airstrikes by the U.S-led coalition to prevent its advance. The Hezbollah-negotiated deal allowed the evacuation in exchange for locating the remains of Lebanese soldiers and the release of fighters. On Thursday, a captive Hezbollah fighter was released.

The head of the Britain-based Syrian Observatory for Human Rights said buses and vehicles crossed into Deir el-Zour province Wednesday. Last week, the U.S-led coalition said it ended surveillance of the convoy after a Russian request.