By Eyanir Chinea and Alexandra Ulmer
CARACAS (Reuters) - Venezuelan opposition supporters took to the streets again on Monday to protest a grinding economic crisis and an erosion of democracy under leftist President Nicolas Maduro, in the first sustained wave of anti-government demonstrations in three years.
A Supreme Court decision in late March to assume the functions of the opposition-led congress sparked outcry among a population already suffering from triple-digit inflation and widespread shortages of basic goods.
The court quickly overturned the most controversial part of its decision but the move triggered condemnation at home and abroad, as did Friday's news that the national comptroller had banned politician Henrique Capriles - seen as the opposition's best hope in a presidential election scheduled for next year - from office for 15 years.
Brazilian Foreign Minister Aloysio Nunes and Organization of American States chief Luis Almagro called on Venezuela on Monday to restore full democracy and set a timeline for elections, increasing diplomatic pressure on Maduro.
Four nationwide protests in the last 10 days degenerated into clashes between security forces and youths throwing rocks.
Protesters led demonstrations in several cities on Monday, blocking the main highway through Caracas in the morning until they were dispersed by National Guard troops firing tear gas.
"It's working, the government is scared and making mistakes like banning Capriles, because that generates more support for him," said homemaker Imelda Guerrero, 66, who said her three children have emigrated due to the crisis.
"But this is will be a long struggle, it's only just starting," she added in Caracas.
OPPOSITION DEMANDS ELECTIONS
A smaller group later moved to the upscale Altamira district, a common site for protests during the last 15 years, where demonstrators set up barricades of tires and burning trash along a major avenue.
A Reuters witness saw securities forces on motorcycles detain a half-dozen of those involved.
The opposition is demanding a date for gubernatorial elections that were supposed to take place last year, as well as a timeline for future elections including the presidential vote, which is constitutionally mandated for 2018.
Despite the surge in protests, many Venezuelans are pessimistic that marches can bring about change, scared of violent clashes, or simply too busy trying to find food.
Maduro's unpopular government accuses the opposition of fomenting violence to lay the ground for a foreign invasion.
Some 188 protesters, most of them students, were arrested in the period April 4-8 and 57 are still behind bars, rights group Penal Forum said on Monday.
Nine people, including two teenagers, were arrested for breaking into an office of the Supreme Court and vandalizing it at the end of Saturday's march. And a 19-year-old was shot dead in violence around protests on Thursday.
The government has come under increased pressure from American and European countries that have condemned violence in Venezuela and the ban on Capriles.
Maduro, a former bus driver and union leader who accuses foreign countries of "meddling," travelled to communist ally Cuba on Sunday for a meeting of the ALBA bloc, which includes Venezuela's leftist allies in Latin America including Nicaragua, Bolivia and Cuba.
(Additional reporting by Diego Ore; Writing by Alexandra Ulmer and Brian Ellsworth; Editing by Frances Kerry)