Tunisian President Beji Caid Essebsi has declared a 30-day state of emergency across the country following a bomb explosion which claimed the lives of 12 people.
Essebsi also imposed an overnight curfew in the capital, Tunis, in response to the blast he described as a terrorist attack.
"I proclaim a state of emergency for 30 days under the terms of law and a curfew in greater Tunis from 9:00 pm (2000 GMT) until 5:00 am tomorrow," Essebsi said.
Speaking on national television, the Tunisian president called on the international community to cooperate with his country in its “war against terrorism,” which has left hundreds of people dead around the world in recent weeks.
An emergency meeting of Tunisia’s security council was also scheduled for Wednesday.
On Tuesday, a bus carrying Tunisian presidential guards, a security force responsible for protecting the president, was the target of a bomb blast in the capital’s Mohamed V avenue.
A Tunisian security source at the site said "most of the agents who were on the bus are dead."
According to witness Bassem Trifi, a human rights lawyer, the explosion hit the driver’s side of the bus. No group or individual immediately claimed responsible for the attack.
The deadly blast took place just days after Tunis increased its security level in the capital and deployed security forces in high numbers.
United Nations Secretary General Ban Ki-moon condemned the attack.
Earlier this month, Tunisian authorities announced that they had dismantled a network which had planned to carry out attacks at polling stations and hotels in the city of Sousse, the site of a terrorist attack earlier this year.
Some 60 people were killed in two attacks in Tunisia, which were claimed by members of Daesh Takfiri group operating mainly in Syria and Iraq.