LONDON (AFP) - British police helping the Tunisian authorities investigate the beach massacre that left 30 Britons dead said on Wednesday they were linking it to an earlier attack on a Tunis museum.
The Britons were among 38 holidaymakers gunned down at a beach hotel near Sousse on June 26, three months after a shooting at the Bardo Museum in the capital Tunis in March. Both attacks were claimed by the Islamic State group.
"The attack at the Bardo museum which left 22 dead, including one British woman, is now being linked to the Sousse murders," said Commander Richard Walton, head of counter-terrorism at London's Metropolitan Police.
He said he could not give further details because the investigation was still live.
"I can confirm that a team of officers, led by a senior detective from the Met's Counter Terrorism Command, are working closely with the Tunisian authorities on both investigations and we have advised the coroner of the connection between the two," he said.
Tunisian authorities have previously said that the gunman in Sousse received training in Libya at the same time as the two men behind the Bardo attack and may well have known each other, although they could not confirm that.
In the June attack at the Imperial Marhaba Hotel, 23-year-old student Seifeddine Rezgui gunned down foreign tourists after pulling a Kalashnikov assault rifle from a beach umbrella.
Many of the British survivors flew home shortly afterwards and detectives here have been collecting details of their harrowing experiences.
Walton said that officers had so far taken 459 witness statements and were examining more than 370 photo and video files from mobile phones.
A number of witnesses had referred to a second gunman wearing red shorts. The police commander said investigators now believe he was a member of beach security, although they "retain an open mind on this issue".
He added that about 150 people had been arrested in Tunisia in relation to the Sousse attack, of whom 15 have been charged with terrorism offences and remain in custody.
Walton praised the Tunisian investigation but the attack has caused tensions between Britain and Tunisia after London advised its tourists to stay away, warning that local authorities could not protect them.