Lima, Peru ? Army troops and police clashed with demonstrators blocking highways Wednesday after President Alejandro Toledo declared a national state of emergency to control spreading protests.

By nightfall, security forces had managed to open up Peru’s 1,500-mile Pan American Highway, which had been cut in 64 spots by rocks and smoldering tires placed by angry farmers and their supporters, Defense Minister Aurelio Loret de Mola said.

In the most violent clash, soldiers and police fired tear gas and then bullets at protesters blocking the highway outside Barranca, 100 miles northwest of Lima. The crowd resisted and hurled rocks at the security forces before scattering as troops advanced.

Health Minister Alberto Sanabria said 95 demonstrators had been detained throughout Peru and 16 policemen hurt in the clashes. There were no figures available on injuries among protesters.

Thousands of travelers, including children and the ill, have been stranded since Monday as farmers sought to stop farm produce from getting to Lima and other cities.

In Chiclayo, 410 miles northwest of Lima, police fired tear gas and arrested striking teachers. In Pativilca, 140 miles northwest of Lima, demonstrators stoned cars and ransacked buses.

Toledo went on national television late Tuesday night to announce the drastic measure.

“Tolerance has its limit,” he said. “We have the responsibility to govern for 26 million Peruvians. We have the responsibility to protect citizens and the public order.”

The 30-day state of emergency gives police and the military the authority to use force to clear the highways, restore order, detain strikers and enter homes without warrants. It also limits freedom of movement and prohibits public assembly.

Tens of thousands of farmers had joined striking teachers, government health workers and judiciary employees in spreading protests that turned increasingly violent. In the central Andes near the city of Jauja, some 2,000 farmers on Tuesday stoned a contingent of 30 policemen trying to clear a highway, injuring seven of them.

The farmers are demanding lower taxes on their crops and protection from imports. The other groups are seeking wage increases.