Activists opposed to mining operations in Peru's southeastern Puno region mobilized for a fresh wave of protests after a respite that allowed stores to briefly open for business.
The protesters, mostly Aymara Indians, are angry over plans by a Canadian company to open a silver mine in the area, fearing it will pollute the water and leave few local benefits. They also oppose other area mines.
More than 3,000 Aymara protesters reached the city of Puno Monday and were threatening to again block all access to the city of 120,000 on the shores of Lake Titicaca, the highest navigable lake in the world.
The crowd spent the night in the city's main square.
"The strike will not be lifted until the government gives us a solution," said Aymara leader Javier Pari at a late Monday rally in downtown Puno.
The protest began at Desaguadero, on the Peru-Bolivia border, and spread on May 24 to Puno, the regional capital. For days demonstrators blocked the railroad, the airport and all roads in and out of the city.
During a brief respite on Monday most of the 300 foreign tourists trapped in the city managed to drive to the airport in the nearby city of Juliaca, while others fled when the port on Lake Titicaca re-opened.
Puno residents were also able to get needed supplies via Juliaca for several hours.
The protest began as a widespread demand for the revocation of a silver mining concession granted to Canada-based Bear Creek Mining Corporation. It soon escalated into a broader indictment of mining in the region.
An angry mob on Friday set fire to a customs building following a night of violence in which three government offices were looted.
The demonstrators agreed on Saturday to halt the protests in talks with the government, in exchange for a 12-month freeze on all regional mining activity.
However, rank-and-file protesters rejected the agreement the next day and said the demonstrations would resume.
In Lima, Interior Minister Miguel Hidalgo appealed for calm.
"All forceful demonstrations should end," he said. "Several days have gone by, there have been considerable economic losses, and we are less than six days ahead of an important vote," referring to an upcoming presidential election.
But protest leader Walter Aduviri told AFP that the activists will continue demonstrating "until the final consequences," seeking a presidential decree banning all mining in the region.
The planned protests come just ahead of a June 5 presidential election pitting leftist populist Ollanta Humala against Keiko Fujimori, the daughter of former president Alberto Fujimori, imprisoned for crimes against humanity.
Polls show the two are in a statistical tie, and the Puno region is considered an Humala stronghold.
Aduviri has threatened to prevent voting if protesters' demands are not met.