International investigators on Tuesday (April 17th) entered a Syrian town hit by an alleged chemical attack, after days of delay and warnings by Western powers that crucial evidence had likely been removed, AFP reported.

The suspected gas attack on April 7th on Douma, near Damascus, reportedly left more than 40 people dead and was blamed by Western powers on the regime of Syrian President Bashar al-Assad.

In response, the US, France and Britain conducted unprecedented missile strikes on Syrian military installations before dawn Saturday.

"Experts from the chemical weapons committee enter the town of Douma," state news agency SANA wrote, referring to the Organisation for the Prohibition of Chemical Weapons (OPCW).

The inspectors arrived in Damascus on the day of the Western strikes but had not been allowed to enter Douma.

France and the US appeared to question the purpose of such a mission, warning that any incriminating evidence had likely been removed by now.

"It is highly likely that evidence and essential elements disappear from the site, which is completely controlled by the Russian and Syrian armies," the French foreign ministry said.

The US ambassador to the OPCW, Ken Ward, had claimed Monday that the Russians had already visited the site and "may have tampered with it".