BRASILIA, Brazil -- Brazilian truckers continued striking Wednesday in several states, torching toll booths and crippling traffic in some areas. More protests demanding better public services were expected in Sao Paulo, the country's biggest city.

Police said truckers either partially or completely blocked interstate and intercity highways in at least six states and burned eight toll booths on the highway between the cities of Cosmopolis and Paulinia in the state of Sao Paulo.

In most cases, truckers left one lane open so that buses, ambulances and passenger cars could bypass the blockades they erected.

It was the third day truckers struck to demand lower toll fares and fuel prices and improved highway conditions.

Organizers of Wednesday's protest said in an emailed statement that demonstrators would take to the streets to demand free public transpiration, a reduction in the work week from 44 to 40 hours, rent control and the earmarking of 10 per cent of the country's gross domestic product for education.

The wave of protests that hit Brazil on June 17 began as opposition to transportation fare hikes, then expanded to include anger at high taxes, poor services, and high spending for the World Cup. Demonstrations eventually coalesced around the issue of rampant government corruption.

The Senate on Tuesday night approved legislation banning people convicted of corruption and other crimes from holding civil servant jobs. The so-called "clean record law" must still be passed by the lower house of Congress, the Chamber of Deputies.

In 2009, a similar law prohibited politicians from running for public office for eight years if they had been convicted of crimes including abuse of power, corruption, money laundering and drug trafficking.

"We want to fight corruption at all levels," Sen. Eunicio Oliveira said.

The Senate last week passed legislation labeling corruption a "heinous crime." It also increases minimum prison terms from two to four years for those found guilty of corruption.

Also in response to the protesters, Congress' lower house on Tuesday night shelved a proposed bill that would allow psychologists to treat homosexuality as a disorder or pathology.

The bill was approved last month by a Brazilian congressional human rights committee.