Tunisian President Kais Saied's decision to suspend Parliament and dismiss his prime minister sparked rallies of support and also protests at home, where the biggest political party decried it as a coup.
Foreign governments also voiced concern.
Here are reactions from countries and organisations around the world to Sunday's shock announcement and to further developments on Monday, when the defence minister was also sacked.
Washington voiced alarm and called for all sides to adhere to "democratic principles".
Later, US Secretary of State Antony Blinken spoke by telephone with Mr Saied to urge respect for democracy and asked him to "maintain open dialogue with all political actors and the Tunisian people", the State Department said.
"He encouraged President Saied to adhere to the principles of democracy and human rights that are the basis of governance in Tunisia," it said.
"We call on all Tunisian actors to respect the constitution, its institutions and the rule of law," an EU representative said.
"We also call on them to remain calm and to avoid any resort to violence in order to preserve the stability of the country."
Arab League Secretary General Ahmed Aboul Gheit, in a call with the Tunisian foreign minister, expressed "complete support for the Tunisian people".
In a statement, the league said it hoped Tunisia would "move swiftly past the current turbulent phase in restoring stability".
Saudi Foreign Minister Prince Faisal bin Farhan stressed "the kingdom's keenness on the security, stability and prosperity of Tunisia", during a phone call with his Tunisian counterpart.
Jordanian Foreign Minister Ayman Safadi expressed hope "that our brothers will overcome these difficult situations in a way that preserves the safety, security and stability of Tunisia".
Kremlin spokesman Dmitri Peskov said Russia was monitoring developments in Tunisia.
"We hope that nothing will threaten the stability and security of the people of that country," he told reporters.
Paris urged a return "as soon as possible" to the "normal functioning" of government in Tunisia.
The foreign ministry called "on all of the country's political forces to avoid any form of violence and to preserve the country's democratic gains".
A spokeswoman for the Foreign Ministry, Maria Adebahr, told reporters that Germany hoped Tunisia would return "as soon as possible to constitutional order".
"Democracy has taken roots in Tunisia since 2011", Ms Adebahr said, referring to the year of the popular revolution that toppled dictator Zine El Abidine Ben Ali.
Germany was very worried, she said, but "we don't want to speak of a coup d'etat".
The Qatari foreign ministry expressed "hope ... that the Tunisian parties would adopt the path of dialogue to overcome the crisis".
The Foreign Ministry said it was "deeply concerned" and called for the restoration of "democratic legitimacy" in Tunisia.
President Recep Tayyip Erdogan's spokesman, Ibrahim Kalin, tweeted: "We reject the suspension of the democratic process and the disregard of the people's democratic will in friendly and brotherly Tunisia.
"We condemn initiatives that lack constitutional legitimacy and public support. We believe Tunisia democracy will emerge stronger from this process."