BAKHCHISARAY, Crimea (Reuters) - Russian riot police in two trucks rolled down a dirt track on the outskirts of the Crimean town of Bakhchisaray, past a woman standing outside her house in a floral-print dressing gown, before climbing out and forming a line across the road.
The officers, all wearing balaclava masks and some carrying truncheons and automatic weapons, stood in silence as a crowd of about 20 local residents came out of their houses and asked them to explain what they were doing there.
"We haven't done anything wrong and we're being treated like criminals," one man in a black Adidas track suit can be heard saying in amateur video footage of the standoff on the morning of May 12.
Two years after Russia annexed Crimea from Ukraine, police are intensifying their scrutiny of the Crimean Tatars, a mainly Muslim community that makes up about 15 percent of the peninsula's population. Searches of properties, raids, and arrests have become commonplace, say local people.
The Tatars, who were deported from the region by Stalin during World War Two and only allowed back four decades later, have largely opposed Russian rule.
The authorities say the police have a good reason for their activities. They say they have evidence that some Crimean Tatars belong to Islamist groups they deem extremist, and are acting to prevent them carrying out acts of terrorism. They have not disclosed evidence of any violence or planning for acts of violence.
But many Crimean Tatars - and some independent human rights activists - say the community is being targeted by police because of its opposition to Moscow.
The people being targeted by police "are ideological opponents of the authorities, and the Russian Federation sees them as a threat", said Emil Kurbedinov, a lawyer representing four Crimean Tatars awaiting trial on terrorism-related charges.
Russia has been in de facto control of Crimea since March 2014 when it sent in troops to drive out Ukrainian forces after a popular uprising overthrew Kiev's pro-Moscow president and replaced him with a Western-backed administration. Moscow later oversaw a referendum in which a majority of the region's voters chose to become part of Russia.
The tensions between the Crimean Tatars and their new rulers in Moscow have been well-documented.
Brussels and Washington have condemned Russia's decision to suspend the Mejlis, the Crimean Tatars' semi-official legislature. The Eurovision song contest was won by a Crimean Tatar singing about her people's history of oppression by Moscow.
The police campaign targeting Crimean Tatars has drawn little comment from foreign governments, however, perhaps because it is difficult to separate officials' legitimate concerns about Islamist extremism from other possible motives.
Some of the people who have been arrested in the police sweep are adherents of Hizb ut Tahrir, a group which seeks the establishment of an Islamic caliphate. The organization - which says it is non-violent - is banned in countries including Russia and Germany but is legal in Britain and the United States, as well as in Ukraine.
Ruslan Balbek, deputy prime minister in the Moscow-backed Crimean government, told Reuters the security services had to act to root out dangerous forms of Islamism.
"Neither Hizb ut Tahrir, nor Wahabbism, nor any forms of political Islam are characteristic to the Crimean Tatar people," Balbek, himself a Crimean Tatar, told Reuters in an interview.
"There is often a confusion of concepts: people interpret a crackdown on religious sects which are banned in Russia ... as a persecution of the Crimean Tatars," he said.
The Moscow-backed prosecutor's office in Crimea said it had opened 28 criminal prosecutions into "extremist and terrorist manifestations" since the start of 2015.
However, rights campaigners and community activists say the Islamist problem is being over-stated. They say that, while there are some hardliners, the vast majority of Crimean Tatar Muslims are moderate.
Fazyl Amzayev, Hizb ut Tahrir's chief spokesman in Ukraine, who is based in Crimea, said there were no confirmed cases of the group's supporters being involved in terrorism. He declined to say how many adherents the group has, citing the risk of reprisals from the authorities.
Crimean Tatar leaders also say that many of those arrested may have no link to Hizb ut Tahrir and that police tactics - including showing up in large numbers in Crimean Tatar communities - are designed to intimidate, not fight crime.
"In the Russian Federation, every citizen is supposed to be loyal to the existing authorities. They did not get that loyalty from the Crimean Tatar people," said Ilmi Umerov, deputy head of the Mejlis, now suspended by Moscow.
The police tactics are also causing concern among Kremlin advisers. The presidential Human Rights Council, a body that advises President Vladimir Putin, will discuss the treatment of Crimean Tatars when it meets in June, said Nikolai Svanidze, a council member.
He told Reuters there were some examples of possible oppression of Crimean Tatars. "We're keeping this question in our sights," he said.
The riot police who drove into the outskirts of Bakhchisaray last month arrived shortly after security service officers in plain clothes searched a home there, according to local residents. The details of the search were unclear.
This would be typical of the pattern followed by security forces carrying out raids on Crimean Tartar targets, according to interviews with Crimean Tatar activists, lawyers, independent rights activists and local residents.
They say that plain-clothes security service officers, often driving vehicles without license plates, show up at homes or businesses owned by Crimean Tatars suspected of Islamist links. They often break down the door, conduct a search and take the suspects away for questioning.
In several cases, truck-loads of riot police have been sent into the areas afterwards to prevent or break up any protests by local people, the sources say.
Another video from Bakhchisaray, shot on a mobile phone, showed a police operation underway at a cafe. The footage was shot on the same day as the two truck-loads of police arrived on the outskirts of the town, May 12, but it was not clear if the two operations were linked.
Inside the cafe, decorated with Arabic inscriptions, police were detaining suspects. In the square outside, several dozen police in full riot gear formed lines to hold back a crowd of about 100 people who had gathered to protest.
Many in the crowd recited Muslim prayers, while others shouted "Shame on you!" to the police.
Additional reporting by Pavel Polityuk in KIEV and Olga Petrova in MOSCOW; Editing by Christian Lowe and Pravin Char