By early March 2011, some parts of Libya had tipped out of Gaddafi's control, coming under the control of a coalition of opposition forces, including soldiers who decided to support the rebels. Eastern Libya, centred on the port city of Benghazi, was said to be firmly in the hands of the opposition, while Tripoli and its environs remained in dispute. Pro-Gaddafi forces were able to respond militarily to rebel pushes in Western Libya and launched a counterattack along the coast toward Benghazi, the "de facto" centre of the uprising. The town of Zawiya, from Tripoli, was bombarded by air force planes and army tanks and seized by Jamahiriya troops, "exercising a level of brutality not yet seen in the conflict."