Security officials have killed two gunmen to end a standoff at a leading Tunisian Museum where 17 tourists and one police officer were fatally killed, amid fears that others involved in the incident are still at large.

In total, 21 people were killed at the Bardo Museum in the capital, Tunis, Tunisian Prime Minister Habib Essid said. The death toll included the gunmen, who have not yet been identified.

The victims included 17 tourists from Italy, Germany, Poland and Spain, Mr Essid said. Unconfirmed reports suggest that two British tourists were among those shot dead.

Another 22 tourists were injured and another two Tunisian men, Mr Essid said, adding that the gunmen may have had had two or three helpers. An operation is still underway to find the others, he said according to The Guardian.

The policeman was killed as security forces attempted to save those who were held hostage inside the museum, according to the interior ministry spokesman Mohamed Ali Aroui.

Describing the shooting as a "terrorist attack", Mr Aroui told reporters earlier today that "two or more terrorists armed with Kalashnikovs" killed seven foreigners at the Bardo Museum in the capital, Tunis, Al Jazeera reported.

Amateur video footage believed to be from the scene before the gunmen were shot appears to show Tunisian forces surrounding the museum.

Live television footage showed tourists running for shelter, covered by security forces aiming rifles into the air.

Built in the 15th century, the museum stands adjacent to the national Parliament building, and includes one of the world's largest collections of Roman mosaics.

Images reportedly taken by a hostage which emerged on social media before police officers killed the gunmen, appear to show around 30 tourists gathered inside a room adorned with mosaics.

The UK Foreign Office said it was unable to confirm reports that two Britons were among the dead.

A spokesman said: "We are urgently looking into the serious situation in Tunisia."

At least three Polish citizens and two Italians were wounded in the attack, the countries' respective officials said prior to Mr Essid's announcement.

An official at the Italian foreign ministry in Rome added that around 100 Italians were in the area and had been taken to safety by Tunisian police.

In pictures: Bardo Museum shooting Show all 8 1 /8 In pictures: Bardo Museum shooting In pictures: Bardo Museum shooting Bardo Museum shooting Tourists and visitors from the Bardo museum are evacuated in Tunis. AP Photo/Hassene Dridi In pictures: Bardo Museum shooting Bardo Museum shooting A victim is evacuated from the Bardo museum in Tunis. AP Photo/Hassene Dridi In pictures: Bardo Museum shooting Bardo Museum shooting Police officers are seen on the pavement outside parliament, which is nearby the Bardo Museum. REUTERS/Zoubeir Souissi In pictures: Bardo Museum shooting Bardo Museum shooting Members of the Tunisian security services take up positions where gunmen reportedly took hostages near the country's parliament, outside the Bardo Museum, Tunis. EPA/MOHAMED MESSARA In pictures: Bardo Museum shooting Bardo Museum shooting Members of the Tunisian police force take up a position near the country's parliament after gunmen reportedly took hostages, outside the Bardo Museum. EPA/MOHAMED MESSARA In pictures: Bardo Museum shooting Bardo Museum shooting Members of the Tunisian security services operate behind a van. EPA/MOHAMED MESSARA In pictures: Bardo Museum shooting Bardo Museum shooting Police officers stand guard outside parliament in Tunis. REUTERS/Zoubeir Souissi In pictures: Bardo Museum shooting Bardo Museum shooting A victim is being evacuated by rescue workers outside the Bardo musum in Tunis. AP Photo/Hassene Dridi

French Prime Minister Manuel Carlos Valls has said France would help its former colony in the wake of the tragic attack.

"We are condemning this terrorist attack in the strongest terms," Valls said speaking after a meeting with European Commission President Jean-Claude Juncker in Brussels.

"We are standing by the Tunisian government. We are very alert about how the situation is evolving," he added.

French foreign minister Laurent Fabius said in a statement minutes after the crisis ended: "It is not by chance that today's terrorism affects a country that represents hope for the Arab world. The hope for peace, the hope for stability, the hope for democracy. This hope must live."



The Parliament building in Tunisia where gunshots were reportedly fired (Image: Wikimedia Commons) (WikimediaCommons/Yamen)

Earlier, the TAP state media agency reported that gunshots broke out at the country's parliament at midday.

A witness near the parliament told Reuters a large police presence was moving to evacuate the government building.

The incident marks the first attack on a tourist site in years in Tunisia, since its shaky young democracy was founded in 2011.

The Bardo Museum in Tunis where eight people have been shot dead. (Getty Images) (FETHI BELAID/AFP/GettyImages)

It is unclear who the attackers are. However, a researcher at the Quilliam think tank has tweeted a message from a prominent Isil supporter that today's attack is the start of a wave of terrorism in Tunisia.

Tunisia has struggled with violence at the hands of Islamic extremists in recent years, who emerged after the country's 2011 uprising against autocrat Zine El-Abidine Ben Ali.

The attack is likely to damage Tunisia's efforts to revive its tourism industry.

It comes the day after Tunisian security officials confirmed the death in neighbouring Libya of a leading suspect in Tunisian terror attacks and the killings of two opposition figures in Tunisia.