Protests have raged on for a fourth night in Istanbul following the arrest of the city’s mayor, part of the largest demonstrations Turkey has seen in more than a decade.

Ekrem Imamoglu, a rival of Turkish President Recep Tayyip Erdogan, was detained on Wednesday, days before he was due to be selected as a 2028 presidential candidate.

Imamoglu appeared at an Istanbul court on Saturday after being detained on charges including corruption and aiding terrorist groups. He has denied the allegations.

In a speech on Saturday, Erdogan repeated his condemnation of the unrest and accused Imamoglu’s opposition Republican People’s Party (CHP) of trying to “disturb the peace and polarise our people”.

Outside the mayor’s office in Istanbul, before the protests had even properly begun, tear gas hung in the air.

As the crowds had grown throughout the evening, it became hard to breathe as round after round was fired to disperse demonstrators.

Chanting “rights, law, justice”, people of all ages defied a government ban on gatherings to protest against what they see as an unlawful detention.

One young woman, dressed in black and wearing a face mask, told the BBC she was not protesting for political reasons or because she supports the opposition, but instead to defend democracy.

“I’m here for justice, I’m here for liberty. We’re free people and Turkish people cannot accept this. This is against our behaviour and culture.”

Another woman, who had brought her 11-year-old son to the protests, said she wanted to bring him as she is worried about his future.

“It’s getting harder to live in Turkey day by day, we can’t control our lives, we can’t choose who we want and there is no real justice here.”

It is very telling that no one the BBC spoke to felt comfortable giving their name or showing their face.

Many on the streets on Saturday night, braving arrest themselves, told the BBC they were out fighting for a future they could believe in.

For the past four nights, thousands have taken to the streets across Turkey in largely peaceful demonstrations.

Authorities tried to stifle the street demonstrations with a four-day ban on all gatherings in Istanbul, which was extended to Ankara and Izmir as protests spread across the country.

Since Thursday, riot police have repeatedly clashed with protestors and could be seen firing pepper gas and water cannons towards crowds of demonstrators.

Turkish authorities said 343 people were arrested on Friday night, the third day of protests, across the country.

Imamoglu is seen as one of Erdogan’s most formidable political rivals. He is the only person running in the CHP’s presidential candidate selection, which is set to take place on Sunday.

However, on Wednesday, he was one of more than 100 people, including other politicians, journalists and businessmen, detained as part of an investigation.

A day before his arrest, Istanbul University announced it was revoking Imamoglu’s degree due to alleged irregularities, a measure – which if upheld – would put his ability to run as president into doubt.

According to the Turkish constitution, presidents must have completed higher education to hold office.

Erdogan has held office for the past 22 years, as both prime minister and president of Turkey. However, due to term limits, he cannot run for office again in 2028 unless he changes the constitution.

Opposition figures say the arrests are politically motivated. But the Ministry of Justice has criticised those who link Erdogan to the arrests, and insist on their judicial independence.