The 48-hour protests come in the wake of the student protests earlier this month [Reuters]

Protesters barricaded roads and burned tires in parts of Chile's capital, as a two-day national strike began against Sebastian Pinera, the country's unpopular president.

At least 18 flaming barricades were set up early on Wednesday morning, according to the Telam news service. Police responded with tear gas and water cannons. At least 2,000 officers were deployed in the city.

The strike, which was called for by Chile's main umbrella labour union in support of a massive demonstration movement for better access to cheaper and higher-quality education, started slow.

While previous governments have faced one-day national strikes, it was the first 48-hour national strike since the fall of a 17-year dictatorship in 1990.

Government spokesperson Andres Chadwick said police defused some protests earlier on Wednesday, and that beyond traffic disruptions, the situation was "normal".

The government said it would not tolerate roadblocks and estimated that the strike would cost Chile about $200m each day.

Police have clashed with protesters in recent months as hundreds of thousands of people took to the streets to rail against Pinera, who, according to a recent poll, is the least popular leader in the two decades since the end of Pinochet's rule. The demonstrations have reportedly been the largest since the dictatorship ended.

While Latin America's economy expanded 6.6 per cent this year and is an investor magnet thanks to prudent fiscal and monetary policies, many ordinary Chileans feel that they are not reaping the benefits of economic prosperity.