The Cathedral of St. Khatarina and St. Mauritius in Magdeburg, Germany is lit with France's national colors late Saturday in solidarity with the victims of Friday's deadly Paris terror attacks. The attacks are the latest violence claimed by radical Islamist groups since the destruction of the twin towers in New York in 2001. World leaders joined a heavily-guarded summit in Turkey on Sunday to forge a united front against jihadist violence after the Paris gun and bomb assaults, but face stark divisions over conflict-riven Syria. Photos: IC

People pray, place flowers and light candles in tribute to the victims of the attacks near the Bataclan concert venue in Paris, France on Saturday. An unprecedented string of attacks in Paris on Friday left at least 120 dead and more than 350 injured.

People lay flowers for the victims of the Paris attacks at the French Embassy in Beijing, China on Sunday. French police on Sunday detained relatives and friends of one of the seven gunmen and suicide bombers for the attacks, as the investigation widened.

Louisiana State University students cheer with painted chests with the message "Pray for Paris," in honor of the victims of the attacks, in the second half of an NCAA college football game against Arkansas in Baton Rouge, Louisiana, US on Saturday.

Indian sand artist Sudarshan Pattnaik works on a sand sculpture paying tribute to the victims of the Paris attack, bearing the message "Stop terrorism, pray for Paris victims," at Bhubaneswar, Orissa, India on Saturday.