Bolivia's main cities were plunged into chaos on Thursday as a public transport strike triggered by an 83 per cent hike in gasoline prices crippled daily life in the Andean nation.The military guarded the presidential palace in thecapital La Paz, where public transport was almost at acomplete standstill. Though the city has long boasted of being a main electoral stronghold for President Evo Morales, residents have come out en mass to reject the fuel price increases.Faced with widespread complaints after his government announced price hikes that include a 73-per cent rise in the price of diesel, Morales announced a 20-per cent minimum salary increase late on Wednesday in hopes of quelling the unrest. But two powerful unions and civic groups in the land-locked South American nation nonetheless announced strikes and marches in a bid to derail the price increases.