Hours after an unidentified gunmen opened fire near a road block set up by striking teachers, protesters in Mexico's colonial city of Oaxaca said they were holding firm in their demands that the state governor resign, while the federal government criticizes the groups. "Our position is clear," said leader of the Section 22 protest group Ezequiel Gonzales, "to continue until Ulises Ruiz leaves, and his exit is not negotiable." The streets around the centre have been occupied by months by thousands of striking teachers and left-wing activists trying to bring down the state government, headed by Governor Ulises Ruiz. Ambushes and drive-by shootings similar to Friday's (September 29) attack have plagued the protests and five activists have been shot dead since the conflict began. Teachers put up new checkpoints on the streets leading to the city's main square and piled rocks to be thrown at police if they try to dislodge the protesters. Ruiz, who his opponents say ordered the shootings, refuses to resign and wants federal police to end the protests, which have left elegant buildings daubed with graffiti and devastated the local tourist industry, normally one of the city's main sources of income. President Vicente Fox has promised to resolve the conflict before leaving office at the end of November but federal government-brokered talks between the protesters and Ruiz have so far failed to end the stalemate. Fox's Interior Minister Carlos Abascal vowed to return Oaxaca to normal. "I want to emphasize that we've given ample, sufficient response to the legal and legitimate claims of these organisations," he told journalists in Mexico City. He did not put a deadline on ending the crisis or say whether federal forces would break up the protests. "It is urgent that APPO and Section 22 stop holding hostage the infancy of the Oaxaca state and Oaxaca City residents." Ruiz is from the Institutional Revolutionary Party which ruled Mexico for 71 years until 2000. More than 1,000 anti-governor protesters marching the 270 miles (430 km) from Oaxaca to Mexico City are expected to arrive over the weekend. They hope to meet with government negotiators. Fox says he has not ruled out the use of force to recapture the town if talks fail. Restaurants, hotels and stores hard hit by the exodus of tourists and have been closed since Thursday in a two-day shut-down designed to pressure authorities to resolve the crisis. The protests started with a teachers' strike over wages and against the governor, who they accuse of corruption and say has polarised the state by using heavy handed policing to resolve political disputes. The teachers refuse to return to classes despite being threatened with the loss of their jobs. Oaxaca state, famed for beaches, highland towns and elaborate cuisine, is also one of Mexico's most impoverished regions and tensions often run high between its poor Indian population and authorities.