ROME, April 17 (Xinhua) -- Italy opposes chemical warfare but did not participate in Friday's U.S.-led air strikes against chemical weapons facilities in Syria, Prime Minister Paolo Gentiloni said Tuesday.

Reporting to the Lower House of parliament, Gentiloni said chemical warfare is "unacceptable".

"One hundred years from the end of World War I (which saw the use of mustard gas), adapting to the idea of having to live with chemical weapons again, of somehow legitimizing them, is unacceptable," the outgoing center-left prime minister said.

"We cannot accept this," he reiterated. "There is every evidence" that chemical weapons were used in April 7 attack on Douma, a rebel-held suburb of Damascus, Gentiloni said.

The April 14 U.S.-UK-France strike against chemical weapons manufacturing sites was "motivated, targeted, and circumscribed", and there is no evidence any civilians were killed, the Italian leader said.

Italy did not participate in the strike, and no military action departed from Italian territory, Gentiloni said.

The U.S. has four military bases in Italy, including one at Sigonella in Sicily.

Gentiloni stressed that the crisis in Syria, where a bloody civil war has been raging in the Middle Eastern country since early 2011, cannot be resolved through the use of force but through negotiations.