Tunisian authorities have arrested a group of suspects associated with the attacker who carried out a beach hotel attack in which 39 people were killed, the country’s interior minister said on Monday.
Interior minister Najem Gharsalli did not give further details, but he said officials also were still verifying whether the attacker had been trained in neighbouring Libya in jihadist camps.
Meanwhile, a British tourist who witnessed the Tunisian massacre claims a second gunman may have been involved in the atrocity.
Steve Johnson, a retired police officer, said he saw a man in red shorts wielding a gun as well as black-clad Seifeddine Rezgui.
He told the BBC he witnessed the second gunman as the carnage unfolded in Sousse, and was later informed by Tunisian police that he too had been shot dead.
Mr Johnson escaped from the beach into the spa of the hotel after the shooting began and led a group of people on to the rooftop.
He told BBC Radio 4’s World at One: “We were in a position to look down over the pool and the terrace and could see everything below us.
“There was gunfire going during that time and by the time we had got up to the third floor and were looking down, we saw a number of bodies on the terrace and the steps and saw another guy — because my colleague had seen the man in the black shorts and shirt on the beach shooting people and now we have got a guy in red shorts with a gun walking down through the terrace and down by the pool and it looked like local people running away from him.”
Asked if he was sure there were definitely two attackers, he said: “What I am saying is the one on the beach — definitely. The one by the pool? Who else would have a gun in swimming shorts walking down in that sort of environment and why were people running away from him?”
Mr Johnson said he spoke to police after seeing TV reports focused on the suspect in black.
“We were obviously concerned now because we know that we have seen another guy in red shorts with a gun and, to our mind, is he still in the hotel? Is he still at large?”
He said that, along with a friend, he told a senior police officer there was a second terrorist involved in the atrocity.
The Tunisian officer showed them a picture of the man in black but “we said ‘no, it’s not him, he’s the one from the beach, this is a man in red shorts’”.
“He (the Tunisian officer) said ‘yes, we have killed the man in the red shorts as well’ and we said ‘congratulations’.”
Mr Johnson claimed that he had seen the body of a man in red shorts in a hotel corridor.
“When we were being brought back by armed police officers from the spa into the main hotel, (in) the corridor that they brought us through there was the body of a native male in red shorts, red swimming shorts, who had been shot and was partially covered over.
“That he was the guy, I can’t be 100 per cent sure, but he looked very much like the man that we had seen running around with a gun by the pool.”
On Sunday, investigators said they were "sure" the attacker, a 24-year-old student killed in the assault on the Imperial Marhaba Hotel, had help, the Interior Ministry said.
Mohammed Ali Aroui told The Associated Press that "we are sure that others helped but did not participate" except indirectly.
He said the father of the attacker, identified as Seifeddine Rezgui, and three roommates in Kairouan where he studied were detained for questioning.
The attack on tourists at a beach is expected to be a huge blow to Tunisia’s tourism sector, which made up nearly 15 per cent of the country’s gross domestic product in 2014.
It also comes after 22 people were killed in March at the National Bardo Museum in Tunis.
Agencies