Russian air strikes, which began in September 2015, have killed at least 1,000 people, including more than 300 children, monitoring groups said.

"At least 1,505 people have been killed in Russian air strikes since they started in September 2015. We have documented their names and can say at least 346 of them were children and only at least 47 were fighters," Bassam al-Ahmad, spokesperson for the Violations Documentation Centre in Syria (VDC), told Al Jazeera on Wednesday.

The VDC is an independent, non-governmental organisation that has been monitoring the conflict in Syria since April 2011.

The UK-based Syrian Observatory for Human Rights put the death toll at 1,015, adding that 238 of those killed were children. The Observatory also said that at least 1,141 fighters had been killed, including fighters from the Islamic State of Iraq and the Levant (ISIL) group.

First Russian air strike targeted civilians

Khalid, a volunteer from the Syria Civil Defence, said civilians were the target on the first day Russia launched its air strike campaign on September 30.

"Hearing Russian on the radio? We knew straight away that this was a different type of attack. The targets were 100 percent civilians. A whole neighbourhood was destroyed in Talbiseh, including 60 homes of civilians," Khaled said.

Known also as the White Helmets, the Syria Civil Defence is a group of volunteer rescuers formed in 2013 that now numbers more than 2,700 volunteers.

'Campaign is against ISIL'

Russia says the goal of its military operation in Syria is in response to a request by Syrian President Bashar al-Assad and on the basis of a decision granted by its parliament.

Russia launched its military operation in Syria in September 2015, and it says the campaign is against ISIL and al-Nusra front groups.

According to Russia's official news agency, TASS, the air campaign consists of 69 warplanes and helicopters.

Death toll in Russian raids on Syria's Idlib nears 100

Russia's defence ministry says it also uses its planes to drop humanitarian aid to civilians in besieged areas.

"Since January 15, transport aircraft of the Syrian Air Force has projected 50 tonnes of cargos with food products and articles of first necessity by the Russian P-7 parachute platforms," the ministry said in a press release.

In an interview with the the German newspaper Bild, Russian President Vladimir Putin said his country's aim in the Syrian conflict was to prevent another Iraq or Libya.

"One should try anything to support the legitimate rulers in Syria. But this does not mean that everything can just stay the same. Once the stabilisation of the country has progressed, a constitutional reform has to follow, and then early presidential elections.

"Only the Syrian people can decide who should govern the country in the future."

The Syrian conflict has killed at least 250,000 people, according to the UN, and more than half of Syria's prewar population of 22.4 million has been internally displaced or have fled abroad.