Protesters briefly scuffled with hundreds of police sent to contain protests in eight central highland provinces after roadblocks hampered transport of key flower and farm products and threatened to push up consumer prices.
Stick-wielding Indians clad in ponchos and short-rimmed hats blocked highways with burning slabs of wood in Tabacundo, a city 28 miles (45 km) north of Quito, to demand President Alfredo Palacio quit free-trade talks with Washington.
"We will not leave until the government tells us they will not sign a deal," said Rosa, a 56-year-old peasant who walked two hours from her village in the Andes mountains to participate in the demonstration.
"The deal will corrupt our traditions and kill our way of life," said Rosa, who like others in the protests asked that her last name not be used.
About 800 policemen were sent to reinforce highways north and south of Quito, but no violence was reported, a police spokesman said.
Ecuador, which started Andean trade pact talks in May 2004, has been deadlocked with the United States, mostly over agricultural issues. Neighboring Colombia and Peru have reached trade agreements with Washington.
Near the Tabacundo roadblock lie lush flower farms. Ecuador expects the flower export industry to generate around $380 million this year, but it could suffer heavy losses from the blockades.
"We are losing hundreds of thousands of dollars a day because we cannot take our flowers to the airports," said Santiago Saenz, of the association of flower producers and exporters.
The demonstration has also hurt trade of basic food products such as corn, potatoes and milk between the eight central provinces where traffic has been disrupted, local economists said.
Economy Minister Diego Borja said consumer prices could be pushed up by the internal trade disruption caused by the protests and affect this year's inflation target of between 2.3 and 2.5 percent.
Faced with pressure to drop the free-trade pact, Palacio has said he will not sign any deal that is unfair to Ecuadoreans. Palacio has struggled with protests and strikes since coming to office last year after Congress fired his predecessor.
Indians, who represent a large part of the country's rural labor force, said the trade deal will put them at a disadvantage with American farmers and further disrupt their culture.
Protesters say more will join, including union workers and peasants from the coast, to pressure the government. Between 12 and 30 percent of Ecuador's 13 million citizens are Indian, according to estimates. (Additional reporting by Carlos Andrade Garcia in Quito)