Tunisian troops blocked the head of parliament from entering the building early Monday, hours after President Kais Saied announced he had fired Prime Minister Hichem Mechichi and suspended parliament for 30 days.
Saied, a political independent, said he was acting in response to the country's economic woes and political deadlock and added that the country's constitution gave him that authority.
The move follows weeks of political turbulence in the country – fueled in part by public anger over the government's handling of the COVID-19 pandemic.
Rached Ghannouchi, the parliament speaker and head of the dominant Ennahdha party, called the president's actions a "coup" and said the legislature would continue its work.
Two other main parties in parliament also called it a coup, which the president rejected.
A U.S. State Department spokesman said that the United States is closely monitoring the developments and that any solution to Tunisia's political and economic troubles should be based on the country's constitution.
"Tunisia must not squander its democratic gains," State Department spokesman Ned Price said in a statement Monday.
U.S. Representatives Gregory Meeks, chairman of the House Foreign Affairs Committee, and Ted Deutch, chairman of the Subcommittee on Middle East, North Africa and Global Counterterrorism, said they were "seriously concerned" by the events in Tunisia.
"We call on all parties to respect and adhere to the rule of law," they said in a statement Monday.
Saied's announcement drew crowds of demonstrators into the streets of the capital, Tunis, and elsewhere to celebrate, reflecting people's anger at parliament to address the country's problems.
There were also protesters outside the parliament building who were against the president's actions, and clashes took place between the opposing groups.
Tunisian authorities shut down a live broadcast of Qatar's Al-Jazeera TV, alleging that its correspondent appeared to encourage the small crowd of protesters to chant against the government. The broadcaster reported that its office in the Tunisian capital was sealed shut and that journalists were not being allowed to enter.
Tunisia has struggled economically for years, and along with political challenges, it has dealt with a spike in COVID-19 cases and deaths.
Political analyst Amin Mustafa told VOA that "most Tunisians have been badly hurt by the ongoing economic crisis and high unemployment, so the issue of suspending parliament is not likely to arouse a strong negative reaction."
The influential Tunisian Federation of Labor declared Monday that it considers "all measures taken by the president to be legal."
Edward Yeranian in Cairo contributed to this report. Some information for this report came from The Associated Press, AFP and Reuters.