Protesters have cut off access to the Bolivian mining city of Potosi in a dispute with the government over infrastructure investment.
Access to the city of more than 130,000 people has been blocked by thousands of protesters as part of an 11-day strike.
Local media report that the city has almost run out of petrol, food and money.
Around 100 foreigners, mostly Argentine tourists, have been trapped by the roadblocks.
Many of the Argentines had travelled to the area for the Pope’s visit last week.
Twenty French youth volunteer workers, three Britons and one Russian are also among the stranded foreigners.
One of the stranded British tourists told the AFP news agency that police were working on a plan to get them out by bus.
The authorities admit that they have so far been powerless to break the picket lines.