Story highlights Muslim leaders warn their community against lure of ISIS

France says 570 of its nationals are fighting with ISIS

Paris (CNN) Muslim leaders gathered at a makeshift memorial in Paris on Monday to pay their respects to those killed in terror attacks and warn members of their community against joining ISIS.

Several of the attackers are believed to have been French nationals who traveled to Syria to join ISIS. According to the French interior ministry, France is the largest source of European jihadis in Iraq and Syria with at least 570 French nationals fighting in the ranks of ISIS.

Abdalali Mamoun, an imam at a southern Paris mosque, was one of a 20-strong group who came to lay flowers near the Bataclan theater where scores of people attending a rock concert were gunned down. He urged young French Muslims to steer clear of ISIS's unholy war.

"You're mistaken," Mamoun said. "You're mistaken in supporting that movement, ISIS.

Photos: Landmarks turn blue, white and red in support for Paris Photos: Landmarks turn blue, white and red in support for Paris The Eiffel Tower in Paris is illuminated in the French national colors on Monday, November 16. Displays of support for the French people were evident at landmarks around the globe after the deadly terrorist attacks in Paris on Friday, November 13. Hide Caption 1 of 27 Photos: Landmarks turn blue, white and red in support for Paris The world's tallest tower, Burj Khalifa, is lit in French colors Sunday, November 15 in Dubai, United Arab Emirates. Hide Caption 2 of 27 Photos: Landmarks turn blue, white and red in support for Paris A man walks past Jerusalem's Old City walls, which were illuminated in the colors of the French flag on November 15. Hide Caption 3 of 27 Photos: Landmarks turn blue, white and red in support for Paris The Tokyo Skytree is lit up in the colors of the French flag on November 15. Hide Caption 4 of 27 Photos: Landmarks turn blue, white and red in support for Paris A paddlewheel riverboat passes under a bridge in Nashville, Tennessee, on Saturday, November 14. Hide Caption 5 of 27 Photos: Landmarks turn blue, white and red in support for Paris Estonia's government building in Tallinn glows with the French national colors on November 14. Hide Caption 6 of 27 Photos: Landmarks turn blue, white and red in support for Paris The Peace Bridge, which connects Canada and the United States, glows with the colors of the French flag November 14 in Buffalo, New York. Hide Caption 7 of 27 Photos: Landmarks turn blue, white and red in support for Paris The Staples Center's ice is lit up with the colors of the French flag before the start of an NHL hockey game on November 14. Hide Caption 8 of 27 Photos: Landmarks turn blue, white and red in support for Paris The Christ the Redeemer statue in Rio de Janeiro is illuminated in French national colors on November 14. Hide Caption 9 of 27 Photos: Landmarks turn blue, white and red in support for Paris As the sun sets, London's Tower Bridge is lit in a succession of blue, white and red on November 14. Hide Caption 10 of 27 Photos: Landmarks turn blue, white and red in support for Paris The Palace Albania building in Belgrade, Serbia, is lit in the colors of the French flag on November 14. Hide Caption 11 of 27 Photos: Landmarks turn blue, white and red in support for Paris The White Tower, a symbol of the Greek city of Thessaloniki, is lit with the colors of the French national flag on November 14. Hide Caption 12 of 27 Photos: Landmarks turn blue, white and red in support for Paris The Southbank Centre in London lights the cloudy sky on November 14. Hide Caption 13 of 27 Photos: Landmarks turn blue, white and red in support for Paris People in Tel Aviv, Israel, light candles and hold posters during a gathering to honor the victims of the Paris attacks on November 14. Hide Caption 14 of 27 Photos: Landmarks turn blue, white and red in support for Paris The London Eye reflects onto the River Thames on November 14. Hide Caption 15 of 27 Photos: Landmarks turn blue, white and red in support for Paris People cross the street past the Cibeles Palace, Madrid's town hall, on November 14. Hide Caption 16 of 27 Photos: Landmarks turn blue, white and red in support for Paris London's National Gallery is illuminated in blue, white and red lights on November 14. Hide Caption 17 of 27 Photos: Landmarks turn blue, white and red in support for Paris Friends Arena in Solna, Sweden, is illuminated in blue, white and red on November 14. Hide Caption 18 of 27 Photos: Landmarks turn blue, white and red in support for Paris The Brandenburg Gate in Berlin stands illuminated in the colors of the French flag as people lay candles and flowers at the adjacent French Embassy on November 14. Hide Caption 19 of 27 Photos: Landmarks turn blue, white and red in support for Paris A ferry travels past the Oriental Pearl Tower in Shanghai, China, on November 14. Hide Caption 20 of 27 Photos: Landmarks turn blue, white and red in support for Paris As a sign of solidarity , Australia's Sydney Opera House is illuminated in the colors of the French flag on November 14. Hide Caption 21 of 27 Photos: Landmarks turn blue, white and red in support for Paris The Calgary Tower in Alberta, Canada, is lit up with the colors of the French flag on Friday, November 13. Hide Caption 22 of 27 Photos: Landmarks turn blue, white and red in support for Paris The Senate building in Mexico City is lit up blue, white and red on November 13. Hide Caption 23 of 27 Photos: Landmarks turn blue, white and red in support for Paris The Auckland Museum in New Zealand is illuminated in French colors on November 13. Hide Caption 24 of 27 Photos: Landmarks turn blue, white and red in support for Paris In New York, the antenna of One World Trade Center was lit on November 13.

Hide Caption 25 of 27 Photos: Landmarks turn blue, white and red in support for Paris The Eiffel Tower replica at Paris Las Vegas was dimmed over the weekend. Hide Caption 26 of 27 Photos: Landmarks turn blue, white and red in support for Paris The Taipei 101 building in Taiwan is illuminated blue, white and red. Have you seen other world landmarks lit up in tribute to France? Share your photos with CNN by tagging #CNNiReport on social networks. Hide Caption 27 of 27

"It will drag you to your death, to hellfire, because suicide and slaughter are not permitted in Islam."

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