Tensions flared at Vienna Airport on Sunday night following the arrival of flotilla activists, after one supporter was arrested and dragged away by police, just a day after a similar scene unfolded at an airport in Spain. 

The three returning activists were greeted by supporters in the terminal with Palestinian flags and chants such as 'from the river to the sea,' which some interpret as a call for the destruction of Israel.

As the situation escalated and the group became loud and obstructive, around 10 police officers intervened.

One activist, identified as former Austrian ski pro Julian Schütter, was arrested and had to be restrained on the ground by officers as he continued to chant 'free Palestine.'

He can be heard telling police: 'I’m just coming back from your role models,' appearing to suggest they were treating him the same way the Israelis had. 

Footage shared by the Global Sumud Flotilla shows the man being dragged away by police as fellow supporters attempt to stop them.

The Austrian police force defended their actions, claiming they used 'proportionate force.'

In a video released later, Schütter said: 'I was arrested because I was apparently too loud and lying in the way in the terminal.' 

He further claimed two cops kneeled on him and showed his arm with two bruises, adding: 'One is from Austrian police and the other from the [IDF].'

The incident came just one day after a separate group of flotilla activists returned to Spain, where scenes descended into chaos as Basque police beat them with batons. 

The situation occurred as supporters gathered in the arrivals hall of Bilbao Airport to welcome six campaigners as they arrived on a flight from Turkey on Saturday.

When a relative of one of the activists tried to approach them, a police officer forcefully prevented him from doing so, leading to scuffles between both sides.

Images showed police striking people with batons at the airport and pinning others to the ground while being jeered by onlookers.

Before this, activists appeared to have blocked the exit for other passengers and police tried to move them. 

Four people were arrested for serious disobedience, resisting arrest and assaulting law enforcement officers, the Basque regional police force, the Ertzaintza, said in a statement. Two of those arrested were activists who had just arrived from Turkey.

'Following what happened at the airport, the Ertzaintza internal affairs division has launched an investigation to determine whether the officers' conduct complied with procedures,' it added.

The Israeli Embassy in Spain meanwhile mockingly demanded an 'explanation' from the Spanish government over the events at Bilbao airport. 

Amnesty International condemned what it described as the 'excessive use of force' by Basque police officers at the airport and called for 'effective accountability' over the incident.

'The images published show no legitimate cause for the use of force,' it added in a statement.

'It is very serious that batons were repeatedly used against people who had already been knocked down and were on the ground.'

After the incident over the weekend, around two thousand protesters took to the streets of Bilbao on Sunday to condemn the Basque police's treatment of the activists.

The Basque regional police force said in a statement yesterday it had launched an investigation to determine if officers complied with procedures. 

On Sunday's march, pro-Palestinian demonstrators carried banners criticising the Basque police force and accusing the local government of being complicit with Zionism.

It comes as Spain was among a series of Western governments on Thursday which expressed their anger after Israeli minister Itamar Ben-Gvir posted a video of himself mocking the activists as they were pinned to the ground in a prison.

Ben-Gvir posted the video to his X account on Wednesday with the caption: 'That's how we welcome the terror supporters. Welcome to Israel.'

The footage shows masked officers aggressively subduing Gaza flotilla activists by pushing them down, forcing them onto all fours, and dragging them across the floor.

The detainees are then seen zip-tied and lined up inside a warehouse, kneeling with their faces pressed to the ground, as the minister waves an Israeli flag and shouts: 

'Welcome to Israel. We're the landlords,' followed by, 'Good job. That's how you do it.'    

Austrian Foreign Minister Beate Meinl-Reisinger also spoke out, criticising Israel's treatment of the activists as 'absolutely unacceptable.' 

The safety of Austrian citizens, she said, was of 'top priority.' 

Hundreds of activists from countries around the world were detained in Israel after they were intercepted at sea last Monday while attempting to break the blockade of the Palestinian territory.

The group included 44 Spanish nationals, according to Spain's foreign ministry.

Around 20 other activists from the flotilla landed at Barcelona airport on Saturday, where they were welcomed by supporters, including Culture Minister Ernest Urtasun.

Organisers alleged on Friday that the activists were subjected to abuse while in Israeli detention - claims that have been denied by Israel.

Global Sumud Flotilla said the group had documented at least 15 cases of sexual abuse, with the worst occurring on one Israeli landing craft which had been converted into a makeshift prison with barbed wire and shipping containers.

Detainees were thrown into the containers and beaten over the head and ribs, the group claimed in a statement.

They suffered multiple cases of sexual abuse, including 'humiliating strip searches, sexual taunting, groping and pulling of genitals, and multiple accounts of rape.'

'At least 12 sexual assaults have been documented on that vessel alone, including anal rape and forcible penetration by a handgun,' it added, although the claims have been strongly disputed.

Germany said some of its nationals had been injured and that some accusations were 'serious', without giving further details.

A legal source in Italy said prosecutors there were investigating possible crimes including kidnapping and sexual assault. 

Israel's prison service has strongly denied the allegations.

'The allegations raised are false and entirely without factual basis,' an Israeli prison service spokesperson said in a statement.

'All prisoners and detainees are held in accordance with the law, with full regard for their basic rights and under the supervision of professional and trained prison staff,' it said. 

'Medical care is provided according to professional medical judgment and in accordance with Ministry of Health guidelines.'