PODGORICA, Montenegro — Protesters clashed with hundreds of riot police in the old capital of Montenegro on Saturday, setting up blockades of tires and large rocks ahead of the inauguration of the new head of the Serbian Orthodox Church in the small Balkan nation.

The ceremony planned for Sunday in Cetinje has angered opponents of the Serbian church in Montenegro, which declared independence from neighboring Serbia in 2006.

On Saturday, hundreds of protesters confronted the police in Cetinje and briefly removed some of the protective metal fences around the monastery where the inauguration of Mitropolitan Joanikije is supposed to take place. Montenegrin state RTCG TV said the protesters broke through a police blockade at the entrance to Cetinje and threw stones at them, shouting “This is Montenegro!” and “This is not Serbia!”

Waving red Montenegrin flags with a double-headed eagle, protesters then set up road barriers with trash containers, car tires and large rocks to prevent church and state dignitaries from coming to the inauguration on Sunday.

Montenegrins remain deeply divided over their country’s ties with neighboring Serbia and the Serbian Orthodox Church, which is the nation’s dominant religious institution. Around 30 percent of Montenegro’s 620,000 people consider themselves Serb.

Thousands protested last month in Cetinje, demanding that the inauguration be held somewhere else. The church has refused to change its plans.

Since Montenegro split from Serbia, pro-independence Montenegrins have advocated for a recognized Orthodox Christian church that is separate from the Serbian one.

Montenegrin authorities have urged calm during the weekend ceremonies, which start with the arrival Saturday evening of the head of the Serbian Orthodox Church, Patriarch Porfirije, in Podgorica, Montenegro’s capital.

Porfirije is set to attend Sunday’s inauguration of Joanikije, whose predecessor as the church’s leader in Montenegro, Amfilohije, died in October after contracting COVID-19.

Illustrating the deep ethnic divide, thousands of people waving Serbian flags gathered in front of the main Serbian Orthodox church in Podgorica on Saturday to welcome the patriarch. Many were bused to the capital from Serbia.

The Serbian Orthodox Church played a key role in demonstrations last year that helped topple a a long-ruling pro-Western government in Montenegro. The new government now includes staunchly pro-Serb and pro-Russian parties.

Montenegro’s previous authorities led the country to independence from Serbia and defied Russia to join NATO in 2017. Montenegro also is seeking to become a European Union member.