NEW : Human Rights Watch blames both sides for ` ` serious . '' The UN peacekeeping chief accuses Gbagbo 's government of a ` ` ' '' He says they used a lull in fighting to strengthen their positions . The UN may use force if Gbagbo rival Ouattara 's hotel is attacked .
NEW : Human Rights Watch blames both sides for `` serious abuses '' The U.N. peacekeeping chief accuses Gbagbo 's forces of a `` trick '' He says they used a lull in fighting to reinforce their positions . The U.N. may use force if Gbagbo rival Ouattara 's hotel is attacked .