Ukrainian army tanks ride through a checkpoint near Gorlivka, in the Donetsk region, on February 23, 2015 (AFP Photo/Anatolii Stepanov)
Brazilian police take cover from shooting by alleged drug traffickers, as a protest against violence by security forces takes place at the Mare slum, in Rio de Janeiro, Brazil, Monday, Feb. 23, 2015. Mare is one of several impoverished areas in Rio where police or soldiers have tried to push out gangs and set up permanent posts as part of efforts to make Rio safer ahead of the 2016 Olympics. But many residents complain of heavy-handed tactics by police. (AP Photo/Silvia Izquierdo)
Brazilian soldiers guard an entrance to the Mare slum during a protest against violence by security forces, in Rio de Janeiro, Brazil, Monday, Feb. 23, 2015. (AP Photo/Silvia Izquierdo)
In this photo taken on Thursday, Feb. 19, 2015, Chadian soldiers on top of a truck, left, speak to Cameroon soldiers, right, standing next to the truck, on the border between Cameroon and Nigeria as they form part of the force to combat regional Islamic extremists force's including Boko Haram, near the town of Fotokol, Cameroon. A girl suicide bomber as young as 10 blew herself up at a busy market in the northeastern Nigerian town of Potiskum on Sunday, Feb. 22, 2015, killing four others and seriously wounding 46 people, a witness and hospital records show. (AP Photo/Edwin Kindzeka Moki)
Technicians stand next to a French Navy Rafale fighter jet onboard the French Navy aircraft carrier Charles de Gaulle operating in the Gulf (AFP Photo/Patrick Baz)