Fourteen of the protesters were detained by police after they barricaded the rail line and the access road to their Cateme resettlement area, which lies near the Moatize mine.
The protesters complained about what they say is low-quality housing Vale built for them after they had to make way for its coal mine in the country's northwest, according to report by AFP.
"They put up barricades on the railway with rocks and other things," police commander Jaime Mapume told AFP.
Police later released the detainees, he said.
Vale opened the mine last May, planning to export at least 11 million tonnes of coal a year but is now planning to double this to 22Mt.
The company moved around 980 families to make way for the $1.7 billion mine and most were taken to Cateme, where the company had built 750 houses, schools, a police station and a clinic.
The community has complained about the standard of the housing and accused the company of breaking its promises, Mapume said.
Vale spokeswoman Acucena Paul told AFP that responsibility for the settlement had since passed to the local government, which said planned renovations had been delayed.
"The beneficiaries reported deficiencies of various degrees in the houses, especially cracks and fissures," the Moatize district administrator said in a statement.
First production from the expanded mine is slated for the second half of 2014.
Vale is keen to diversify away from iron ore into coal and has dedicated $4.4 billion of the $6 billion to a new coal terminal at the port of Nacala and a 912km rail line connecting the coal mine with the port.
Vale coal unit general manager for marketing and sales Marcelo Matos reportedly told a coal conference in Maputo that "Moatize is a great alternative to [supply] the growing seaborne market, it's in a very strategic location and there is a lot of interest [for the coal]", according to Reuters.
Mozambique is considered a natural fit for Vale as Brazil and Mozambique share a Portuguese colonial heritage and both have pro-resources governments.
