MOSCOW (Reuters) - Russian war planes will not carry out any air strikes in Syria on Saturday in order to support a nascent cessation of hostilities and to avoid accidentally bombing the wrong targets, the Russian defense ministry said.

A ceasefire agreement entered into force at midnight under a U.S.-Russia plan which the United Nations has called the best hope for peace in the five-year conflict.

"Given the entry into force of the U.N. Security Council resolution that supports the Russian-American agreements on a ceasefire, and to avoid any possible mistakes when carrying out strikes, Russian military planes, including long-range aviation, are not carrying out any flights over Syrian territory on Feb. 27," the defense ministry said.

Sergei Rudskoi, a lieutenant-general in the Russian air force, told reporters at a news briefing that Moscow had sent the United States a list of 6,111 fighters who had signed up to the ceasefire deal and a detailed list of 74 populated areas which should not be bombed.

Rudskoi said hostilities on the ground had been halted in 34 areas mainly in the Hama and Homs provinces. The Kremlin has made clear that the temporary truce does not apply to Islamic State and al Qaeda affiliate the Nusra Front.

(Reporting by Andrew Osborn; editing by Polina Devitt)