"This law is hereby passed. Let it be forwarded to the executive branch," the lower-chamber's president, Roberto Castro, declared following an hours-long overnight debate.

A month of heated demonstrations calling for the center-right Paz to step down have paralyzed the Andean nation, with about 100 protest blockades around Bolivia causing severe food and medicine shortages in major cities.

On Saturday, dozens of riot police backed by military vehicles fired tear gas as they attempted to clear a road in the town of San Julian.

The town is in the Santa Cruz region -- an agricultural breadbasket supplying food to the country's western areas.

Protesters threw stones and burned tires to try to halt the police's advance, according to an AFP reporter at the scene.

The US-backed, pro-business Paz took office in November promising to resolve the country's worst economic crisis in decades, but his unpopular economic reforms and failure to respond to social demands have roused public ire.

He has repeatedly called for dialogue with protesters but on Wednesday announced the bill seeking to amend the country's strict rules on declaring a state of emergency.

The military thus far has had limited involvement in clearing roadblocks, playing a supporting role to the riot police.

The new law would allow troops to use force against protesters and also grants them a "presumption of legality" in situations of conflict.

On Friday, US President Donald Trump's new Shield of the Americas alliance -- an anti-cartel coalition that includes pro-US administrations in Argentina, Bolivia and Chile among other countries -- gave Paz its unequivocal backing.

"We stand with Paz's democratic government as it fights back against attempts to drag Bolivia backwards through cynical efforts to prevent the delivery of food, medicine and other vital supplies to the Bolivian people through fake road blockades," the alliance members said in a statement.