Demonstrators have blockaded highways, looted shops and forced service stations across Mexico to close in a wave of angry protest triggered by a hike of more than 20% in the government-set price of gasoline. The announcement of the price increase came on 1 January – when long queues of cars were already forming at pumps because national oil giant Pemex was unable to supply all gas stations due to problems with oil refining and fuel shortages caused by theft.