(CNN) The UN Security Council (UNSC) failed yet again on Wednesday to pass a resolution condemning last week's chemical weapons attack that killed dozens of people in Syria.

Permanent member Russia vetoed the resolution which sought to condemn the killings and call on the Assad regime to cooperate with an international investigation into the attack.

Over 20 UNSC resolutions on Syria have been passed, most with unanimous backing, but if one of the five permanent members of the UNSC vetoes a draft resolution, it automatically fails.

Wednesday's veto was the eighth time Russia has used its veto -- often along with China -- to torpedo a UN draft resolution on Syria since its civil war began in 2011.

4 October 2011

The first time a UNSC resolution on the Syrian civil war failed to pass came six months after the beginning of the bloody conflict. The council drafted a statement "expressing grave concern at the situation in Syria," and stressing the only solution to the current crisis in Syria was "through an inclusive and Syrian-led political process with the aim of effectively addressing the legitimate aspirations and concerns of the population."

Vetoes: China, Russia

4 February 2012

The Russian and Chinese delegations both used their "no" votes again four months later, blocking a resolution which expressed "grave concern at the deterioration of the situation in Syria," and "profound concern at the death of thousands of people... calling for an immediate end to all violence."

Vetoes: China, Russia

19 July 2012

Later in 2012, the Russians and Chinese again voted against a draft resolution , "condemning the Syrian authorities' increasing use of heavy weapons... and armed violence in all its forms, including by armed opposition groups; Condemning the continued widespread violations of human rights by the Syrian authorities, and armed opposition groups."

Vetoes: China, Russia

22 May 2014

This resolution had sought to ensure "that perpetrators of violations, including those that may constitute crimes against humanity, are held accountable; Condemning the continued widespread violations of human rights by the Syrian authorities, and armed opposition groups."

Vetoes: China, Russia

8 October 2016

Over two years later, as Assad's forces descended on the rebel-held city of Aleppo, the UNSC again attempted to register "outrage at the alarming number of civilian casualties caused by escalating level of violence and indiscriminate aerial bombings in Aleppo."

The resolution referred the "grave.. distress" at the "deterioration of the humanitarian situation in Syria, and the fact that now more than 13.5 million people are in need of humanitarian assistance." Russia was alone in vetoing the draft, China abstained.

Veto: Russia

5 December 2016

As the humanitarian crisis in the besieged town of Aleppo worsened, a resolution called on all "parties to the Syrian conflict" to "cease... any and all attacks in the city of Aleppo to allow urgent humanitarian needs to be addressed for a period of seven days."

It also called for all parties to give the United Nations and its partners "unimpeded humanitarian access."

Both China and Russia voted against the resolution.

Vetoes: China, Russia

28 February 2017

Despite passing a resolution in September 2013 which called for the verification and destruction of Syria's chemical weapon stockpile, China and Russia blocked a draft resolution this February that called for sanctions on parties involved.

Members had been asked to vote on the "imposition of sanctions on entities and individuals deemed to have been involved in the production or use of chemical weapons in Syria."

Vetoes: China, Russia

12 April 2017

The latest resolution to fail at the hands of Russia's veto power came in the wake of the gas attack on Khan Sheikhoun in Idlib province. The draft resolution condemned the attacks and called for an international investigation into the perpetrators. This time China abstained.

Veto: Russia