MOSCOW, January 24 (RIA Novosti) - An estimated 400 international observers will be invited to monitor Russia's March 2 presidential election, the Central Election Commission said on Thursday.

"The procedure of inviting international observers will not differ from the election to the State Duma. About 400 people will be invited," Election Commission Secretary Nikolai Konkin said.

The invitations will be sent out on January 28 after the registration of presidential candidates is completed, he added.

Election authorities have so far registered four candidates for the presidential election: First Deputy Prime Minister Dmitry Medvedev, Communist Party leader Gennady Zyuganov, the Liberal Democratic Party leader Vladimir Zhirinovsky, and an independent candidate, Democratic Party leader Andrei Bogdanov. Medvedev, who has been publicly backed by President Putin, is the clear front-runner.

The Organization for Security and Cooperation in Europe's main election monitoring arm, the Office for Democratic Institutions and Human Rights (ODIHR), will be among those invited to the March election, Konkin said.

The ODIHR boycotted Russia's parliamentary elections held on December 2, citing visa delays and "unprecedented restrictions." The OSCE subsequently declared the elections "not fair."