A gunman who carried out an attack that killed 17 tourists at Tunis’s Bardo museum was known to the authorities, Tunisia’s prime minister has said.

Habib Essi told RTL Radio that security services had flagged up one of the attackers, Yassine Laabidi, but were not aware of “anything specific”, or of any links to known militant groups.

Two Tunisians, a police officer among them, also died in Wednesday’s attack.

Both gunmen were also killed. A search is on for suspects linked to them.

Two or three accomplices are still at large, an interior ministry spokesman told AFP news agency. The spokesman said both attackers were “probably” Tunisian. The second gunman has been named as Hatem Khachnaoui.

The tourists killed in the attack include visitors from Japan, Italy, Colombia, Australia, France, Poland and Spain, officials said.

Officials say more than 40 people, including tourists and Tunisians, were injured.

Speaking after the attack, Tunisia’s President Beji Caid Essebsi said the country was “in a war with terror”.

“These monstrous minorities do not frighten us,” he said in remarks broadcast on national TV. “We will resist them until the deepest end without mercy. “Democracy will win and it will survive.”

At the time of the attack, deputies in the neighbouring parliamentary building were discussing anti-terrorism legislation.

Parliament was evacuated, but later reconvened for an extraordinary session in the evening.

Sayida Ounissi, an MP, told BBC Radio Four’s Today programme that the security services had said parliament was the original target of the attack.

The gunmen went to the museum after they were “blocked before entering parliament”, she said.

Many Tunisians took to the streets of central Tunis to protest against the attack, waving flags and lighting candles outside the museum.

World leaders condemned the attack and expressed their support for Tunisia’s counter-terrorism efforts.

The UN Security Council issued a statement saying no terrorist action could reverse Tunisia’s path towards democracy. The statement offered condolences to those affected by the attack, and called for the perpetrators to be brought to justice.

Meanwhile, White House spokesman Josh Earnest said the US would “continue to stand with our Tunisian partners against terrorist violence”.

EU foreign policy chief Federica Mogherini offered her condolences (in French) to the victims’ families, and said the EU would “fully support Tunisia in the fight against terrorism”.