NEW : Libya says commanders who fire on civilian protesters will face charges . Rockets reportedly hit the city and at least two people were killed . Libyan government says it may request international troops to help stop the violence . U.N. removes its staff in Tripoli for first time since revolution .
NEW : Government says commanders who fire on civilian buildings will face charges . Rockets reportedly struck the airport and at least two people were killed . Libyan government says it may request international troops to help stop the violence . U.N. removes its staff in Tripoli for first time since revolution .