Moscow, April 16 (IANS) Russia has denied interfering with evidence at the site of a suspected chemical weapons attack in Syria's Douma that claimed over 70 lives and led to military intervention by the US, the UK and France.

Russian Foreign Minister Sergei Lavrov in an interview to the BBC said: "I can guarantee that Russia has not tampered with the site."

He spoke as the Organisation for the Prohibition of Chemical Weapons (OPCW) watchdog held an urgent meeting. Its fact-finding team reached Syria on Saturday, the day of the US-led airstrikes against Syrian government targets in response to the April 7 attack.

The team was still not been granted safe passage on Monday, CNN quoted British envoy to the OPCW, Peter Wilson, as saying.

Russian Deputy Foreign Minister Sergei Ryabkov said the team's arrival was hampered by the weekend airstrikes. The OPCW team is tasked with determining whether banned substances were used in the Douma attack, a charge that both Syria and its ally Russia vehemently denied.

Lavrov also denied the use of chemical weapons in Douma and said the event did not take place. "What did take place was the staged thing."

The Russian Foreign Minister asked: "Why the US and its allies had carried out air strikes the day before international inspectors were due to arrive at the site?"

On the air strikes, he repeated the Russian assertion that two-thirds of over 100 missiles fired into Syria on Saturday had failed to reach their targets.

Around 75 people, including children, were killed in the Douma assault, UK officials said, while 500 people were treated in the attack's aftermath with symptoms consistent with chemical weapons exposure, the World Health Organization reported.

British Prime Minister Theresa May and French President Emmanuel Macron were both due to face their respective legislatures later in the day over their decision to join the US in launching missiles at suspected chemical weapons sites in Syria, in an attempt to punish the Bashar al-Assad regime.

Russian President Vladimir Putin dismissed their argument that the strikes were necessary "to prevent the normalization of the use of chemical weapons in Syria, or elsewhere".