BELGRADE (Reuters) - Serbia’s President Aleksandar Vucic announced the arrest of the mayor of a Belgrade suburb on Friday in connection with an attack on a journalist that has become a cause for protesters during nearly two months of anti-government demonstrations.

Serbian President Aleksandar Vucic stands in the St Sava temple in Belgrade, Serbia January 17, 2019. REUTERS/Goran Tomasevic

Vucic, a former ultra-nationalist who has become an advocate of closer ties with the West, is facing weekly demonstrations from opposition groups that accuse him of increasingly authoritarian rule. More protests are planned for Saturday.

Opposition parties and their backers accuse Vucic and his Serbian Progressive Party (SNS) of stifling media freedoms and carrying out attacks on political opponents and journalists.

Demonstrators have been angered in particular by a firebomb attack on the home of a journalist, Milan Jovanovic, in Belgrade’s suburb of Grocka last month. The attackers hurled a firebomb at a car in the garage and fired a pistol at the door as the house burned. The reporter escaped from a rear window.

Jovanovic says he was targeted over his reporting about corruption in his municipality.

In a televised address, Vucic said Grocka’s mayor, who is also an official in the SNS party, had been taken for questioning over his role in the attack on the reporter’s home.

“A party membership card will not save anyone from responsibility. Journalists will be protected no matter for whom they work for ... No one will be protected because of being a politician,” Vucic said.

He also pledged a tougher fight against politically motivated violence and cronyism, including changes in the legislature.

Serbia wants to join the EU, tentatively by 2025, but to do so it must first root out corruption, organized crime, nepotism and red tape.

Earlier this week, at a panel during the World Economic Forum in Davos, Switzerland, Vucic said he was dissatisfied with media freedoms in Serbia and pledged to make an effort to help improve them.