London: At least 15 British nationals have been killed in Friday's attack in Tunisia, the British Foreign and Commonwealth Office (FCO) said on Saturday.

In the latest press release, Minister for the Middle East and North Africa Tobias Ellwood said the number may well rise as "several more have been seriously injured in this horrific attack", Xinhua reported.

Dozens of people, including foreign tourists, were killed when at least one gun man opened fire on a Tunisian beachside hotel in the popular resort of Sousse on Friday, according to Tunisia's interior ministry.

Ellwood said it was "the most significant terrorist attack on the British people" since the London 7/7 bombings in 2005. Prime Minister David Cameron also called the attack on the beach "savage".

Ellwood said the FCO's crisis centre has been working round the clock since the attack, and a rapid deployment team has been mobilised, which is designed to provide urgent assistance during events such as this.

A British police team has also been deployed to assist with the process of identification of victims, and FCO staff are on the ground already, in hospitals and hotels looking after British nationals in conjunction with tour operators and airlines, according to the press release.

The identities of the British victims have not been officially released so far.

(IANS)