BELGRADE – Serbia’s President Aleksandar Vucic on Sunday announced tough measures against anti-government protesters following days of riots in the streets throughout Serbia that have challenged his increasingly autocratic rule in the Balkan country.

In one of his frequent TV addresses to the public, Vucic accused the anti-government demonstrators of “pure terrorism” and reiterated his claims that months of persistent protests against his rule have been orchestrated in the West and aimed at destroying Serbia.

“Our country is in grave danger, they have jeopardized all our values, normal life, each individual,” Vucic said, alleging an elaborate scheme that would eventually install “anarcho-leftist” authorities in the future. He did not offer any concrete evidence for his claims.

“Unless we undertake tougher steps it is a question of days when they (protesters) will kill someone,” Vucic said. “I am saying this for history.”

The stern warnings came after five consecutive nights of clashes between the protesters on one side and police and Vucic’s loyalists on the other. Angry protesters on Saturday evening torched Vucic’s governing Serbian Progressive Party offices in a town in western Serbia, and of other ruling coalition allies.

The demonstrators on Saturday evening also clashed with police in Belgrade, the capital, and in the northern city of Novi Sad. Riot officers used tear gas against demonstrators who hurled stun grenades, flares and bottles at them.

Vucic did not specify what will be the state response that he said would come within a week. But he stressed that a state of emergency is not imminent. Scores of people already have been detained and injured in the past days while police have faced accusations of excessive force and arbitrary detentions of protesters.

“You will witness the determination of the state of Serbia,” Vucic said. “We will use everything at our disposal to restore peace and order in the country.”

The clashes this week marked a major escalation following more than nine months of largely peaceful demonstrations that started after a concrete canopy collapsed at a train station in Serbia’s north, killing 16 people.

Many in Serbia blamed the tragedy on alleged widespread corruption in state-run infrastructure projects that they say fueled poor renovation work. The Serbian president has faced accusations of stifling democratic freedoms while allowing organized crime and corruption to flourish. He has denied this.

Serbia is formally seeking EU membership, but Vucic has maintained strong ties with Russia and China. On Sunday, he praised Russia’s backing for his government against what he called a “colored revolution” against his government.