A gigantic banner proclaiming "Free Palestine" unfurled by Paris Saint-Germain (PSG) supporters at a Champions League match has no place in a football stadium, France's interior minister said on Thursday.

The huge banner covered an entire section of the stadium at PSG's home venue of Parc des Princes in Paris Wednesday night ahead of their defeat at the hands of Spanish rivals Atletico Madrid.

As well as the slogan "Free Palestine", the banner showed a bloodstained Palestinian flag, a gesticulating man with a keffiyeh scarf covering all his face except his eyes, the Al-Aqsa mosque in Jerusalem and a young boy wrapped in the Lebanese flag.

It was shown as Israel presses military operations against Palestinian militant group Hamas in Gaza and the militant Shiite group Hezbollah in Lebanon and international concern grows over civilian casualties.

"This banner had no place in this stadium," right-wing Interior Minister Bruno Retailleau wrote on X.

"I ask PSG to explain itself and the clubs to ensure that politics does not come to damage sport, which must always remain a source of unity," he said, adding such actions were banned by both French football and UEFA.

"If this were to happen again, we will have to consider forbidding banners for clubs that do not enforce the rules," he added.

In a later interview with Sud Radio, Retailleau made no attempt to hide his anger, saying the banner was "unacceptable".

"I want to know more and now how this banner came to be unfurled. The Paris police chief (Laurent Nunez) explained what happened. We agreed on a certain number of things but I am demanding accountability," he added.

'Scandalous'

The banner, which was unfurled by the Paris Ultras Collective (CUP) hard-core fan group, was shown above another slogan which read: "War on the pitch but peace in the world."

"The club was not aware of the plan to display such a message," PSG said in a statement Wednesday evening.

"PSG emphasises the Parc des Princes is -- and must remain -- a place of communion around a shared passion for football and firmly opposes any message of a political nature in the stadium."

The president of the Representative Council of Jewish Institutions in France, Yonathan Arfi, described the banner as "scandalous", saying it depicted "a masked Palestinian fighter" and that it also showed "a map where the State of Israel no longer exists" in an image of the Palestinian keffiyeh.

"This is not a message of peace but a call to hatred," he said.

Hamas's October 7, 2023, attack on Israel that started the war in Gaza resulted in 1,206 deaths, mostly civilians, according to an AFP tally of Israeli official figures.

Israel's retaliatory campaign has killed 43,391 people in Gaza, a majority of them civilians, according to figures from the Hamas-run territory's health ministry, which the United Nations considers reliable.

Hezbollah began a low-intensity cross-border campaign last year in support of ally Hamas after the Palestinian militants' October 7 attack on Israel.

Israel escalated its air raids on Hezbollah strongholds in south Lebanon, Beirut and the eastern Bekaa Valley from September 23, sending in ground troops a week later.

More than 2,600 people have been killed in Israeli strikes since then, according to the Lebanese authorities.