Three British Muslim siblings were left traumatised after being escorted off a plane in London and interrogated on the tarmac as armed police kept watch, after fellow passengers accused them of being members of the Islamic State of Iraq and the Levant (ISIL, also known as ISIS) group.

Sakina Dharas, 24, her sister Maryam, 19, and their brother Ali, 21, were on board EasyJet flight EZY3249 from London's Stansted Airport to the Italian city of Naples on August 17.

Sakina told Al Jazeera on Tuesday that as the plane was about to take off, a crew member ordered the siblings off the aircraft and escorted them down the staircase to the tarmac, where they were met by armed police and an MI5 agent who questioned them for one hour.

Earlier, two passengers - also travelling to Naples - had told authorities that the siblings had been looking at a mobile phone screen that showed either Arabic text or the words "praise be to Allah", Sakina said.

"A passenger on your flight has claimed that you three are members of ISIS," the MI5 agent said to the siblings, according to Sakina, a clinical pharmacist.

"The minute that I saw police standing there, I was extremely emotional," she said.

"We had nothing at all [on our phones]. We don't even speak Arabic, we're [of] Indian [origin]."

Sakina added that her brother had not looked at his phone during their time at Stansted.

The only Arabic in her smartphone is within an app featuring verses from the Quran, she said, which "wasn't open" throughout their time in the airport.

During their one-hour interrogation on the tarmac, Sakina said she was asked to explain - page by page - the details of various entry stamps on her passport. She also showed the MI5 agent recent WhatsApp messages. The siblings provided answers relating to their personal lives and were questioned on their home addresses, workplaces, social media history and parents' professions.

Sakina said the agent told them that he had already performed checks on the family and was simply verifying the information, before warning her that he would be "doing more research on you, and if anything comes back, I'll be here waiting on your return".

The siblings, who are from northwest London. were then allowed back on the plane, which had been delayed.

'Nervous and embarrassed'

"I was extremely nervous and embarrassed," said Sakina, who also wrote an account of the event on her Facebook page.

"I thought, shouldn't they [the agent and police officers] be coming up [on the plane] with us, to show the other passengers that we hadn't done anything wrong, to say, 'Don't worry, it was a misunderstanding?'

"Our holiday in Italy was ruined. It played on our minds the whole time."

EasyJet confirmed the incident to Al Jazeera.

"Following concerns raised by a passenger during the boarding of flight … a member of ground staff requested the assistance of the police who took the decision to talk to three passengers at the bottom of the aircraft steps, before departure," the company said.

"The safety and security of ... passengers and crew is our highest priority which means that if a security concern is raised we will always investigate it as a precautionary measure.

"We would like to apologise for any inconvenience caused to the passengers."

Sakina said she and her siblings were victims of "racial profiling".

"I'm still very annoyed that someone [the accusing passengers] can get away with a blatant lie," she said, adding that she would take legal action "if I knew a way to do so".

READ MORE: US Muslim forced off plane cites Islamophobia

The incident comes at a time of rising Islamophobia in the UK.

Sakina said before the plane experience, that she had received "the odd racist remark about my headscarf".

"With the way things are spun in the media and the climate we're in, we're growing accustomed to it, and desensitised … More education is the best way to battle ignorance," she added.

Muslims around the world are increasingly subject to discrimination as Islam is conflated with "terrorism".

'Humiliating public interrogations'

Rights groups said that while security was important, efforts should be made to protect innocent people.

"It's absolutely right that security is a foremost priority for airlines, and that genuine causes for concern are properly investigated to guarantee the safety of passengers," Rosie Brighouse, a legal officer at the UK-based rights group Liberty, told Al Jazeera.

"However, it is also important that innocent people aren't subjected to humiliating public interrogations, and it is therefore incumbent on the authorities to use their common sense, and subject reported concerns to basic credibility checks, before deciding how to respond."

Yasmine Ahmed, director of Rights Watch UK, said the Dharas' case raised "serious human rights concerns".

"It is completely unacceptable that young, British Muslims are subject to this treatment," she told Al Jazeera.

"The government must immediately explain under what powers they acted, and how it is necessary and proportionate, on the basis of a spurious claim by a fellow passenger, to demand that three young British Muslims disembark an aircraft and be subject to questioning by an MI5 officer and told that the officer may be waiting for them on their return."

Such action carried a "risk [of] having a counterproductive effect by alienating and isolating young, British Muslims," she said.

"Incidents such as these, which unfortunately are all too familiar, raise very serious questions about whether the government is genuinely committed to upholding the very British values that it espouses in its counter terrorism strategy and whether the government's counter terrorism strategy is driven by efficacy or popularism."

Follow Anealla Safdar on Twitter: @anealla