Tripoli , Libya ( CNN ) -- Libya 's new government said it has control of new areas in Bani Walid as the battle rages on for one of the last cities loyal to the ousted ruler . The city center and the northern part of the city are now under government control , said Ali Daeki , a member of the executive crisis committee . Government forces have surrounded the city from all sides , and arrested more than 20 loyalists of former ruler , he said Saturday . Troops loyal to Moammar Gadhafi are now in Dahra , a residential area in the southern part of the city , according to Daeki . National Transitional Council fighters also battling for control in Gadhafi 's hometown of Sirte , and will boost Bani Walid troops as soon as that battle is over , said Abdurahman Bousin , a council spokesman . As the battle for control continues , the U.N. human rights office expressed concern on the number of prisoners in Libya and their treatment . `` It could be up to 7,000 , '' said Mona Rishmawi , a senior official with the group in Geneva , Switzerland . `` At this stage , there is no police infrastructure , there is no prison authorities . ... Right now , the Justice Ministry is not fully functional . '' `` There is allegations and evidence of torture '' in the prisons , she said , citing lawyers , clients and human rights groups . CNN 's Raja Razek and Ingrid Formanek contributed to this report .
Government forces surround the city from all sides , an official says . Troops loyal to Moammar Gadhafi flee to southern part of the city , he says . The rebels have been fighting for more than a week in and around Misrata, which is about 50 miles west of Tripoli.