Hundreds of workers from US aluminium maker Alcoa's Italian plant have clashed with police in a heated protest on the streets of Rome as tensions rise over the planned closure of a Sardinian factory.
A planned sit-in escalated on Monday as protesters demanding the government intervene to save their jobs threw fire-crackers and tried to break through a barrier outside the economic development ministry, only to be pushed back by police.
About 20 people were lightly injured in the skirmish, most of them police officers, Italian media reported.
"We want attention to remain focussed on our demands," independent CUB unionist Angelo Diciotti said.
Wearing T-shirts with the slogan "We are ready for anything", around 500 protesters and trade union representatives shouted anti-government slogans.
"If the factory closes, the whole of the south of Sardinia will die," said worker Paolo Manca, 47, who stressed that the plant is a major employer in a region hit hard by unemployment and said a shutdown would put 2,000 jobs at risk.
The protest took place while talks were held at the ministry over the planned closure, following rumours that either Swiss industrial group Klesch or the commodities giant Glencore may be interested in taking over the site.
"We need concrete answers today. A solution must be found," said Luciano Fenu from the UILM metalworkers' union.
"The main issue is still that energy prices must be lowered" to make the factory competitive on a European level.
The government said that it would ask Klesch and Glencore "to rapidly start talks" on a possible takeover.
The economic development ministry is also in favour of a more gradual cessation of activities at the plant and called for a general debate on how to relaunch the island economy.
Alcoa has began to close down the plant, blaming "factors beyond our control", including "the economic situation and the burdens imposed by the European regulatory system".
The company, which posted a net loss of $US1.151 billion ($A1.11 billion) in 2009, said it was shutting down the foundry in a way that would ensure it could be restarted should an offer be made soon.