A prominent human rights group is calling for the United Nations Security Council to impose a weapons embargo on the Syrian government following airstrikes last week that killed dozens of civilians near Damascus.

In a statement, Human Rights Watch says it spoke with four witnesses who said there were no military targets near the rebel-held town of Douma, where the August 16 airstrikes killed at least 112 people, mostly civilians. It said the nearest base or combatant front line was at least two kilometers away, The Voice of America reported on Thursday.

"Bombing a market full of shoppers and vendors in broad daylight shows the Syrian government's appalling disregard for civilians," said Human Rights Watch's Deputy Middle East Director Nadim Houry. "This latest carnage is another reminder - if any was still needed - of the urgent need for the Security Council to act on its previous resolutions and take steps to stop indiscriminate attacks."

Eyewitnesses say the government bombings targeted popular markets and residential areas in Douma, where opposition fighters have regularly traded fire with the Syrian military during the country's civil war, now in its fifth year.

UN humanitarian chief Stephen O'Brien, who earlier this week finished up a three-day visit to Syria, called the bombings "appalling" and "unacceptable." The world body's political chief, Jeffrey Feltman, referred to the incident as a "war crime."

Syria has not commented on the attacks, except for to criticize UN officials who condemned the incident.

The Syrian government has repeatedly been accused of carrying out indiscriminate attacks on civilian areas during the conflict, which has killed an estimated 250,000 people since it began in 2011.

The August 16 airstrikes are among the deadliest recent attacks carried out by Damascus. Local officials said the bombings injured at least 550 civilians, 40 percent of whom are children, according to the HRW statement.

Armed groups in the area have also "indiscriminately shelled civilians nearby government-held territory, the New York-based rights group's statement added.