pbr Street vendors have clashed with riot police in Mexico's colonial city of Oaxaca after they were prevented from entering Oaxaca's main Zocalo square by the local government.br ppbr Some 100 demonstrators converged close to the main square, where federal police wearing body armor stood shoulder to shoulder.br ppbr At one entrance to the square, protesters lobbed rocks and bottles at police, who responded with volleys of tear gas.br ppbr The scuffles broke out as street sellers, from the indigenous town of Santos Reyes Nopala, tried to reach the square in order set up their stalls selling goods such as crafts and regional clothes. The vendors had occupied the square in the city, famed for its colonial architecture, exotic food and indigenous culture, since June this year.br ppbr Local media reported three protesters were arrested. No serious injuries were reported.br ppbr The square was barricaded by police in order to prepare for the annual "Radish Night," a unique festival held during the Christmas season, where radishes are sculpted into complex figures that compete for prizes.br ppbr In 2006, Oaxaca City, a popular tourist resort, was rocked by a six-month conflict in which leftist activists tried to bring down Oaxaca's governor, who they accused of stealing an election, corruption and heavy-handedness.