The move comes after journalists have used photos and videos posted on social media by troops to gain information on Russia's military involvement in Syria and in Ukraine -- where Kiev and its Western allies say Moscow gives military backing to pro-Russian separatists.

The Russian military has long sought to limit troops' use of social media to avoid information leaks.

The Meduza independent news site wrote that with the bill "we will know less about hazing and the military in Ukraine."

The defence committee of the State Duma lower house of parliament, which wrote the legislation, said it aimed to ensure "national security" in the "sphere of information" and to cover information that is not classed as a military secret.

The bill bans troops from carrying "electronic devices" that can post video and photos online or reveal their geo-locations.

It bans troops, conscripts and reservists from informing media or putting information online that reveals they or others are in the military, describes their duties or gives their location.

It also bans giving out information about the actions of military commanders or the locations of military headquarters.

MPs in the State Duma voted on the key second reading of the bill, which will be followed by a final reading, a senate vote and then a signing by President Vladimir Putin.

The bill warns that foreign secret services and "terrorist" organisations are interested in the activities of Russian troops, particularly those serving in Syria, where Russia has been carrying out a military intervention since 2015 to back President Bashar al-Assad.

It says that information posted online or given to media could be used to form a "prejudiced view of Russia's government policies."

Soldiers who broke the law could be given early discharge.

Basic mobile phones without cameras will not be banned, and troops will still be able to use smartphones while off-duty, the first deputy chief of the defence committee, Andrei Krasov told TASS state news agency.