UK-based Kurdish advocacy groups have condemned the arrest of seven people by counter-terrorism police in London as part of an investigation into the banned Kurdistan Workers’ party, known as the PKK.

Four men aged 23, 27, 56 and 62, and two women aged 31 and 59, were arrested at separate addresses during dawn raids in the capital on Wednesday and remain in custody, the Metropolitan police said. A 31-year-old man was arrested Wednesday afternoon in west London. All are yet to be charged.

Shortly after noon on Wednesday, disorder broke out in Haringey, north London, with large numbers of people turning out to prevent further raids in the area.

Searches were taking place at eight addresses, including the Kurdish Community Centre in Haringey where police said their investigation could take up to two weeks.

Acting commander Helen Flanagan, of the Met’s Counter Terrorism Command, said: “This activity has come about following a significant investigation and operation into activity we believe is linked to the terrorist group PKK. These are targeted arrests of those we suspect of being involved in terrorist activity linked to the group.

“I hope that these arrests show that we will not tolerate any sort of terrorist activity and that we will take action where we believe there is harm being caused to communities here, in the UK or elsewhere.”

The force said there was no imminent threat to the public.

Kurdish community groups called for the “immediate release of those detained” and said the arrests were an “affront to the principles of democracy, justice, and human rights that the UK claims to hold”.

In Haringey Green Lanes, the heart of the UK’s Turkish-speaking community, the usually quiet streets saw scenes of disorder on Wednesday. More than 100 people took to the streets, chanting “shame on you” at police and blocking officers from conducting further raids in the area.

The Kurdish Community Centre was among the sites targeted by police. The Kurdish People’s Assembly in the UK, an advocacy group for the community, is based in the building.

Ishak Milani, co-chair of the Kurdish People’s Assembly in the UK, said: “We, the Kurdish community in London, strongly condemn the recent unjust and heavy-handed raid conducted by British police on our community spaces.

“This aggressive act is not only an attack on our people but also an affront to the principles of democracy, justice, and human rights that the UK claims to uphold.

“We demand accountability for this raid and a clear explanation for the actions taken.”

Speaking outside the centre, Milani said: “We woke up in shock, because the UK police attacked our friends, our political activists. They arrested six of them and raided our community centre, which is really important to us.”

He said police had raided the centre almost on the same date last year: “We are really worried about today. Last year, during our celebrations, they raided our community centre and attacked us.”

Day-Mer, another community group for the Turkish-speaking community in London, condemned the raid on the Kurdish Community Centre and called for “the immediate release of those detained”.

One man said his sister was among those arrested and he was staying with her when the police came. “At 3 o’clock in the morning, I was staying at my sister’s house. They broke the door down, I thought it was a robbery,” he said. “I’ve never seen police like this, they didn’t look like Metropolitan police. They covered their face.”

When he spoke to the Guardian, he had stitches on his forehead and dried blood on his ear. “I ran into my sister’s bedroom. I closed the door then they broke it and they broke my face. Half an hour later, they took me to hospital. Blood was coming down my hand and my face,” he said. “My sister was scared. They called the ambulance and arrested her. I don’t know where she is now.”

He said his sister is often detained when travelling abroad. “My sister, when we go to Europe, they always keep her. Last month, they kept her for eight hours, from 8pm to four in the morning,” she said.

Feryal Clark, the first Kurdish-British Labour MP, said on Wednesday night she was concerned by the raid.

“I have raised the matter with the relevant ministers and I’m in contact with the local authorities & leaders,” the MP for Enfield North posted on X.

The PKK is a separatist group that wants an independent Kurdish state in south-east Turkey. It has been banned in the UK since 2001. The group has been fighting against the Turkish state since the early 1980s.