The year 2014 was the deadliest year yet in Syria's four-year conflict, with over 76,000 killed, activists say.
The UK-based Syrian Observatory for Human Rights said 17,790 of the dead were civilians, including 3,501 children.
Meanwhile more than 15,000 died in conflicts in Iraq in 2014, making it that country's worst year since 2007.
Much of the violence comes as a result of advances by Islamic State and other militants groups in the two countries.
US-led air strikes against Islamic State (IS) militants, fighting between government troops and rebels in Syria, and sectarian violence in Iraq have also accounted for large numbers of deaths.
The air strikes continued on Thursday, with 17 against IS targets near the Syrian cities of Raqqa, Kobane and Deir al-Zour and 12 near the Iraqi cities of Falluja, Mosul and Sinjar.
Meanwhile Syrian President Bashar al-Assad marked the new year with a visit to front-line troops in the Damascus suburb of Jobar.
Mr Assad's Twitter and Facebook accounts showed pictures of him talking to two soldiers by a tank and shaking hands with a third.
The Syrian figures cannot be independently verified, but the Observatory says its draws on sources all across the country.
It said a total of 76,021 had died, slightly up on 2013's toll of 73,447 and bringing the total number of deaths since the conflict began in 2011 to more than 200,000.
Of the 2014 deaths, the Observatory said:
- At least 22,627 were government soldiers or members of pro-government militias
- Almost 17,000 were militants from groups including IS and al-Nusra Front
- More than 15,000 were from moderate rebel groups and Islamist factions
- Civilians made up 17,790 of the dead
On the same day, the Iraqi government published its figures on casualties in 2014.
It said 15,538 people had died and more than 22,000 were injured during the course of the year.
The UK-based NGO Iraq Body Count gave an even higher figure of 17,073 civilian deaths.
The NGO said there was a "new brutality on the ground and renewed attack from the air", with IS and the Iraqi army causing thousands of casualties, and US-led air strikes also responsible for civilian deaths.
The year began with the government losing control of Falluja and parts of Ramadi in western Iraq.
In June, a huge offensive by IS left large parts of northern Iraq in militant hands, including the second city Mosul.
The death toll for 2014 from the Syrian Observatory for Human Rights is just the latest grim statistic from years of war.
- An estimated 10.8m people are in need inside Syria
- Over 10m displaced by the conflict
- 3.2m refugees in neighbouring countries
- More than 50% of the country live in extreme poverty
- Half of the country's children are not in school