A one-minute silence was held simultaneously in Sousse and across the United Kingdom, home to 30 of those killed.
Britain has paused for a minute’s silence to remember the holidaymakers shot dead by a terrorist while they sunbathed on a Tunisian beach last week.
Tunisia’s prime minister, diplomats, Tunisians and tourists gathered on the beach to pay their respects.
The queen and her husband Prince Philip joined in the silence during a visit to Strathclyde University in Glasgow, while Cameron marked the moment in his Witney constituency northwest of London.
As pedestrians and tourists alike bowed their head in London’s Parliament Square during the silence, flags above Whitehall fluttered at half mast, a poignant symbol mirrored at public buildings throughout the country.
The gunman behind the beach attack was killed by police and IS later claimed responsibility for the massacre, a blow to Tunisia’s tourism industry.
Along with the British victims of shooter Seifeddine Rezgui, three Irish nationals, two Germans, one Belgian, one Russian and one Portuguese were also murdered.
Laurie Barton Wright, Frenchgate Centre Manager said: “It is very important to us to observe the minute’s silence in memory of all those who sadly lost their lives in Tunisia”.
Tunisia announced on Thursday that it had arrested eight people, including a woman, “with direct links” to the gun attack.
The first inquest for a British victim of the attacks opened Friday at a London court.
“I think we all live under the threat of terrorism now and I think the “lone wolf” syndrome, we have seen it elsewhere, not just in Tunisia“, he said.
Tunisian investigators believe that accomplices provided the Kalashnikov assault rifle to Rezgui and helped him get to the scene of the shooting.
Coroner Chinyere Inyama is expected to open and adjourn the hearings in which a headline cause of death will be confirmed and the bodies will be released to families.
Tunisian officials say all three gunmen in the two attacks were trained at the same time in jihadist camps over the border in Libya, where factional turmoil has allowed Islamist militant groups to gain ground.
A cortege carrying the coffins of eight of the British nationals killed in the mass shooting in Tunisia are driven from RAF Brize Norton near Oxford on Friday.