Meanwhile, a charity organization in the city of Karachi prepares Iftar for 2,500 to 3,000 fasting individuals daily.
But Gaza's Hamas rulers said a ceasefire was needed to halt the humanitarian crisis.
Israel said it killed an Islamic Group member involved in attacks against Israel, as well as several other militants.
U.S. abstained in a Security Council vote that demanded an immediate ceasefire between Israel and Hamas.
The remaining 14 council members voted for the resolution, which was proposed by the 10 elected members of the body.
The decision was taken "in light of the Islamic State's claiming responsibility for the (Moscow) attack and the threats weighing on our…
In a televised address, Putin said 11 people had been detained, including the four gunmen.
Messages of outrage, shock and support for those affected have since streamed in from around the world.
Eleven of the 15 council members voted for the resolution, but the Russia and China vetoes stopped its passage.
In the 2004 Beslan school siege, Islamist militants took more than 1,000 people, including hundreds of children, hostage.