(Adds details, talks and protests in other states) BRASILIA, April 16 (Reuters) - Hundreds of rural workers occupied the Brazilian land-reform agency's headquarters, and thousands more invaded farms and blocked roads on Monday, demanding the government speed up moves to give land to small farmers and peasants. Protesters stormed the National Agrarian Reform Institute building in the capital Brasilia at dawn and shut the doors to staff. They moved to the cellar by early evening, after authorities agreed to negotiations. There were no reports of injuries. Three activist groups demand that the government accelerate the expropriation of unproductive farms and grant land to squatters throughout the country. "The movement demands the federal government meet its obligation to settle 150,000 families living under plastic sheets throughout the country in the name of the struggle for agrarian reform," the Landless Rural Workers' Movement, or MST, said in a statement. Thousands of MST workers marched in the state of Bahia and several hundreds invaded farms in Goias, Espirito Santo and other states. Five hundred protesters blocked the main road linking Brasilia to Belem in the Amazon region. The protests are part of a month of coordinated activities dubbed "Red April" in honor of 19 peasants killed by police at a settlement in the Amazon jungle 11 years ago. The MST routinely occupies large plantations to pressure the government to grant plots of land and financial aid to poor family farmers. During the latest campaign, which began two weeks ago, peasants have occupied dozens of farms, torched sugar cane, and staged rallies across Brazil. Left-leaning President Luiz Inacio Lula da Silva met with land reform groups on Friday and pledged to consider their demands to ease the criteria for land expropriation.