More than 80 international human rights and aid groups are urging the U.N. Security Council to take real, immediate action against the continuing use of barrel bombs in Syria's grinding civil war.
Thursday's letter comes a week after more than 70 countries expressed "outrage" and demanded that the council prevent Syria's air force from using the weapons, which are prohibited by international humanitarian law because of their indiscriminate nature.
Both Russia and China have vetoed, in the past, any U.N. Resolutions that would use force against the Assad regime to stop his genocide against the civilian population. These aid groups should be blasting Vladimir Putin publicly.
As far as Obama is concerned, the man is MIA either playing golf or sunbathing on a beach somewhere. You would never think the U.S. exists with Barack Obama in power. No doubt, the worst U.S. President ever.
The council meets informally Friday to explore how the international community should respond as Syria's fighting is deep into a fifth year with well over 200,000 killed.
The council more than a year ago called for an end to the use of barrel bombs, but it has not followed up.
The new letter calls the council's periodic expressions of concern since then "woefully inadequate."
But doing more is a challenge, as permanent council member Russia has used its veto power multiple times to block action against its ally Syria since the bloody conflict began with protests against President Bashar Assad.
Russia was not among the dozens of countries that signed last week's letter to Secretary-GeneralBan Ki-moon demanding that the council take action and claiming that "May 2015 was reportedly the deadliest month of the Syrian crisis so far."
More than 11,000 barrel bombs have been dropped in Syria since October, says the announcement for Friday's council meeting, hosted by France and Spain.
In the past month, both the U.N. special envoy for Syria and an independent U.N. commission of inquiry on Syria have condemned the Syrian government's use of barrel bombs.
The new letter signed by Amnesty International, Human Rights Watch, the International Rescue Committee and other organizations says the council should set up a way to track and publicly expose "indiscriminate attacks by any means" in Syria and lay out clear consequences for violators.
The letter, unlike the one from the 71 countries, does not blame one side or another in Syria's conflict.
A separate statement Thursday by Amnesty International goes much further, urging the Security Council to impose an arms embargo on Syria's government and targeted sanctions on anyone responsible for war crimes and crimes against humanity.
AP contributed to this article.