Russian bombs killed at least 679 civilians in Syria in January out of at least 1,382 people killed in total, according to human rights observers' latest calculations.
The Syria Network for Human Rights (SNHR), which documents human rights violations by six different parties to the conflict, also said in its latest report that Syrian government troops killed at least 516 civilians last month, including 69 women and 83 children.
It said the number of women and children killed represented a 30 percent increase on last month, which was a "strong indicator that government troops deliberately targeted civilians."
Out of the 679 recorded deaths due to Russian shelling, 73 were women and 94 were children — more than three per day.
The Islamic State (IS) killed 98 civilians, including 21 women and one child, while the al Nusra Front killed three, according to the report. Syrian opposition groups killed 42 civilians, including nine children and 10 women.
The SNHR makes its calculations using a network of activists, and victims are only included in the figures if they can be verified with their full name and place and date of death. It stresses that the real death toll is very likely to be much higher as neither government troops nor opposition groups record or release casualty figures, and the government does not allow human rights groups to operate in its territories.
On Monday, Russia's Defense Ministry said it had conducted 468 air strikes in Syria in the past week and hit more than 1,300 "terrorist" targets, Russian news agencies reported.
The ministry also said it had delivered more than 200 tons of aid to the besieged Syrian town of Deir al Zor in January.
But British Foreign Secretary Philip Hammond said on Monday Russia was actually targeting the Syrian "moderate opposition," and its intervention had been a major setback for international efforts to find a political solution to the crisis.
"Less than 30 per cent of Russian strikes are against Daesh targets," Hammond said, using an Arabic acronym for IS. "Their intervention is strengthening Daesh on the ground — doing the very opposite of what they claim to be wanting to achieve."
In a clear sign of frustration with the Kremlin, Hammond scolded Putin for paying lip service to a political process aimed at ending the civil war while also bombing opponents of Assad who the West hopes could shape Syria once Assad is gone.
"It's a source of constant grief to me that everything we are doing is being undermined by the Russians," Hammond told Reuters at the Zaatari refugee camp in Jordan, about six miles south of the border with Syria.
Syrian government troops and allied fighters captured hilly countryside near Aleppo on Monday, putting a key supply route used by opposition forces into firing range, according to the UK-based Syrian Observatory for Human Rights monitoring group.
Rebels said the offensive was being conducted with massive Russian air support, despite a promise of goodwill steps by the Syrian government to spur the peace talks on the conflict which are slowly getting underway in Switzerland.
The spokesperson for the opposition's High Negotiations Committee accused Russia on Monday of creating a "new Hitler" in Syria, reported the Sabah Times.
Farah Atassi also said the top priority for the talks in Geneva must be stopping the "unprecedented bombardment by the Syrian regime" of rebel-held suburbs of the Syrian capital Damascus.
The new talks are expected to last for six months, and would see the Syrian regime and the opposition avoid face-to-face discussions, instead negotiating from different rooms through UN mediators, in what has been called "proximity talks."
There have been two previous attempts at holding mediation talks in Geneva — in 2012 and 2014. Meanwhile, the conflict continues and the casualties stack up. Five years of civil war have resulted in 250,000 deaths and the displacement of millions.
Follow VICE News on Twitter: @vicenews