A dispute over Gaza appears to have sparked a fight in the European Parliament on Wednesday, with a left-wing staffer and a center-right MEP accusing each other of aggression — and the Parliament’s initial assessment siding with the MEP’s version of events.

A staffer from left-wing Swedish party Vänsterpartiet on Wednesday accused a Swedish European People’s Party lawmaker, Alice Teodorescu, of physically attacking them. But Teodorescu’s office disputed the story, alleging the Vänsterpartiet aide was the instigator.

Teodorescu’s office said the MEP had been on her way to a meeting before the Parliament’s afternoon debate on the Gaza conflict when the Vänsterpartiet staffer started filming her without her consent, saying they would publish the footage on social media to “tell the world what a terrible person” Teodorescu is. (Teodorescu is known for her staunchly pro-Israel stance.) The MEP then turned her own phone on the Vänsterpartiet staffer, who attempted to grab the device, leading to a physical scuffle.

“Several people in the Parliament saw it happening; it was related to Palestine-Israel tensions, because the MEP is very pro-Israel,” said a Parliament official, who was granted anonymity to speak freely.

The atmosphere in the Parliament on Wednesday was tense as lawmakers debated Israel’s ongoing invasion of the Gaza Strip during a plenary session.

A spokesperson for the Parliament said the violent incident, which was caught on surveillance cameras, was “being investigated as a matter of priority,” and “the initial assessment confirms the MEP’s version of events.”

The spokesperson added that the Parliament was providing assistance to Teodorescu, whose office said she had requested additional security.

Earlier, Vänsterpartiet chief of staff Marie Antman alleged to Swedish news agency TT that the staffer had come into her office “in a state of shock and showed marks that the person had received on his arm. Then it turned out that a Swedish parliamentarian had simply physically attacked my colleague.”

The secretary-general of Teodorescu’s party, the Swedish Christian Democrats, said on social media that the MEP is currently “in shock of the event, that such a thing can happen in a democratic institution.”