TAPACHULA, Mexico, Nov 29 (Reuters) - Some 2,000 migrants and asylum seekers departed the southern Mexican city of Tapachula near the Guatemalan border overnight on Sunday in the latest in a series of caravans setting out for the United States. By Monday morning, the caravan had advanced about 25 kilometers (15 mi) to reach the town of Huehuetan, according to a Reuters witness. The majority of its members were families from Central America and the Caribbean fleeing violence, poverty and growing hunger crises in their home countries. For months, migrants and human rights advocates have denounced the "prison-like" conditions in Tapachula. Under Mexican rules, migrants must wait to process their claims - often for months - before being able to relocate to other parts of the country without fear of deportation. read more Thousands of migrants waited on Monday in an hours-long line inside a stadium where immigration officials had set up a processing center. "In Tapachula, there"s no life for migrants. We don"t have work, we don"t have money to pay for housing," said Atis, a Haitian migrant waiting in line who declined to give his last name. "We"re waiting here at immigration, but if there"s no other option, then we"ll leave here on foot, in another caravan." Last week, the Mexican government transported hundreds of migrants from Tapachula to other states in efforts to head off the formation of more caravans. But tens of thousands of migrants still remain in the city. read more