Original sentence: On the morning of 13 June 2014, during the First Battle of Mariupol, the Azov Battalion, Dnipro-1 Battalion and the National Guard of Ukraine retook the city and key buildings occupied by insurgents killing five militants and destroying an insurgent BRDM-2 armoured vehicle
Edited sentence: On the morning of 13 June 2014, during the First Battle of Mariupol, the Azov Battalion, Dnipro-1 Battalion and the National Guard of Ukraine retook the city and key buildings occupied by insurrectionists killing five militants and destroying an insurrectionist BRDM-2 armoured vehicle