Representatives of Russia and Bolivia vote in the United Nations (UN) Security Council on a bid to renew an international inquiry into chemical weapons attacks in Syria during a meeting at the UN headquarters in New York, U.S., November 16, 2017. REUTERS/Lucas Jackson

UNITED NATIONS (Reuters) - Russia vetoed on Friday a Japanese-drafted U.N. Security Council resolution to extend by one month an international inquiry into who is to blame for chemical weapons attacks in Syria, just a day after Moscow blocked a U.S. push to renew the investigation.

The mandate for the joint inquiry by the United Nations and the Organization for the Prohibition of Chemical Weapons (OPCW), which was unanimously created by the 15-member Security Council in 2015, ends on Friday.

Syrian ally Russia has now cast 11 vetoes on possible Security Council action on Syria since the country’s civil war began in 2011.

The U.N./OPCW investigation found that the Syrian government used the banned nerve agent sarin in an April 4 attack and has also used chlorine as a weapon several times. It blamed Islamic State militants for using mustard gas.