The visitors were killed after a car mowed down their cycling group
ISIS claims Tajikistan attack that killed four tourists
ISIS on Tuesday claimed responsibility for a car-and-knife attack on western tourists in Tajikistan in which two Americans and two Europeans died.
Officials in the ex-Soviet Central Asian nation did not address the ISIS claim but blamed the attack on Sunday on a banned extremist group.
The young men featured in an ISIS-linked video resembled individuals that Tajik authorities identified as the suspects, who were killed by police.
ISIS said in a statement on Monday that several of its soldiers attacked the "citizens of the Crusader coalition".
The four tourists were killed after a car rammed into a group on bicycles, south of the capital Dushanbe, Tajik officials said. After the collision, the driver and passengers got out and attacked the cyclists with knives.
The victims were Jay Austin and Lauren Geoghegan from the United States, Rene Wokke from the Netherlands and Markus Hummel from Switzerland, according to Tajik authorities. Another three people were injured included a woman from Switzerland.
A video posted on an ISIS-linked website on Tuesday showed five men sitting on a hill against the backdrop of a black-and-white ISIS flag and declaring allegiance to the group's leader Abu Bakr Al Baghdadi. The men state they are from Tajikistan and pledge to slaughter disbelievers in the name of Allah. A note accompanying the video said the men took part in the attack.
Tajikistan's Interior Ministry posted photos on Tuesday of what it said were the bodies of the four suspects, lying in a field. Three of the men resembled ones in the ISIS video.
It blamed the attack on the Islamic Renaissance Party of Tajikistan, a party banned several years ago for allegedly plotting to overthrow the government.
Tajikistan, an impoverished, predominantly Muslim nation of about eight million people, was devastated by a five-year civil war with extremist-inspired rebel forces that ended in 1997.
Alarmed by the rise of ISIS in recent years, Tajik authorities have clamped down on behaviour and traditions associated with Islam, regulating how people dress and behave at funerals, and ordering men to shave their beards. Critics say the restrictions could help to radicalize secular Muslims.
The cyclists killed had described their trip as a "dream come true".
Each of the travellers had a blog to document their journey, that took them to the Pamir Highway, a Soviet-era road that stretches across 2,000 kilometres near the border with Afghanistan and has spectacular views.
The Americans explained on their blog SimplyCycling that they had "decided to quit our jobs and bike around the world".
The pair had travelled through Africa and Europe before flying to Kazakhstan in May.
The posts on the site and their Instagram account broke off as they ventured into mountainous Tajikistan, the poorest of the former Soviet states.
"Tajikistan is a tough place to cycle. It is cold and windy and mountainous and, most of all, very, very high," Mr Austin wrote a week ago.
"Really glad I did it. No need to ever do it again," he said, of crossing a Tajik mountain pass at a height of 4,655 metres with thin air and intermittent snow.
Mr Austin had been featured in The Washington Post in 2015 as one of those following a "tiny house" trend and downsizing his daily life to essentials.
'Beautiful, kind people'
The parents of Ms Geoghegan, 29, released a statement on Tuesday saying the trip that their daughter and her partner Mr Austin were enjoying was typical of her "enthusiastic embrace of life's opportunities, her openness to new people and places, and her quest for a better understanding of the world".
They had set out on their adventure in July 2017.
Dutch victim Mr Wokke, a 56-year-old psychologist, was cycling with his partner Kim Postma, a 58-year-old hospital administrator, who was injured in the incident.
The website of Dutch newspaper NRC said the couple were travelling from Bangkok to Tehran and chose to go through Tajikistan to avoid the dangers of Afghanistan.
Mr Wokke was a very experienced traveller and had visited more than 130 countries, according to his brother, Erik.
The pair, from Amsterdam, had left Thailand in February and planned to arrive in Tehran in September before flying back to the Netherlands.
Mr Wokke and Ms Postma described the Pamir Highway on their blog as "the ultimate challenge of this trip".
Swiss cyclist Mr Hummel also kept an online record of his journey with another Swiss national, Marie-Claire Diemand, who was also injured.
In a blog entry entitled "A dream comes true", they explained that they were travelling along the Silk Road from Xi'an in China to Kyrgyzstan.
"Since we are already on the road, we definitely don't want to miss the Pamir Highway in Tajikistan," the pair said.
Their last entry was on July 25, when the whole group was staying in the Tajik town of Khorugh, after adventures including their tent filling with drifts of sand.
They said that on the highway, "we enjoy the silence, the dreamlike landscape and look at the Pamir River and the Afghan side of the valley all day long".
Friends and well-wishers posted messages of condolences on the American victims' SimplyCycling Instagram page.
One, Robert Renner, wrote: "My condolences to the family and friends of Jay and Lauren."
Another, Angela Wuerth, wrote: "I'm so sad that something so tragic could happen to such beautiful, kind people."