On Wednesday around 300 protesters picketed the company’s Moatize mine as well as at a police station, both in the province of Tete, with police firing into the air in an attempt to disperse them.

The protesters claim they have not received adequate compensation from Vale for a loss of livelihood after the company resettled the community five years ago to build the mine.

During the first day of protests on Tuesday, hundreds of demonstrators blocked the entrance to the mine for 24 hours.

"Police are shooting into the air with real bullets. They want people to disperse," community activist Rui de Vasconcelos told AFP by telephone from Tete.

The protests escalated during the second day after the movement’s leader, Refo Agostinho, was arrested, with the police station where Agostinho is held being picketed.

De Vasconcelos said the picketers vowed not to move until Agostinho was freed.

"The constitution gives us the right to protest,” he said.

“Why do police react like this?"

AFP also reported that three people were hurt in the protest while trying to flee police.

Most of the protesters are former brickmakers who used to make and sell mud blocks from clay dug out of the area. They say they are unable to continue to do so in the area they were moved to.

Protesters say the roughly $1900 each brickmaker received from 2008 as initial compensation was not enough and that in some cases these businesses should receive up to $32,000 for the loss of their activities, according to AFP.

Neither government nor Vale say they are prepared to open fresh negotiations with the group after previous negotiations were undertaken for almost a year.

Vale said the protest did not affect production but the rally underscored a lingering problem for the mining firm.

"All access to the company was blocked. The workers had to sneak out of smaller exits," a Vale worker, who asked not to be named, told Reuters by phone.

Earlier this year Vale said it was planning to ship 4.5 million tonnes of coal from Moatize during 2013.