Shayrat Airfield in Homs, Syria is seen in this DigitalGlobe satellite image released by the U.S. Defense Department on April 6, 2017 after announcing U.S. forces conducted a cruise missile strike against the Syrian Air Force airfield. (Reuters photo)

DAMASCUS, April 7 (Xinhua) -- At least four Syrian soldiers were killed by the U.S. missile strike that targeted an airbase in central Syria on Friday, a monitor group reported.

The U.S. missile strike against the Shairat airbase has destroyed the airbase almost completely, according to the Syrian Observatory for Human Rights.

At dawn Friday, the U.S. struck the Syrian airbase in the center province of Homs with tens of Tomahawks missiles.

The state TV said the attack was an "American aggression."

The attack marks the U.S. response to the alleged chemical attack on rebel-held town in northwestern Syria last Tuesday.

Washington accused the Syrian army of being behind the toxic attack that targeted the town of Khan Sheikhoun in Idlib province, an allegation totally denied by Damascus.

Activists of the Syrian Observatory for Human Rights said over 70 people were killed in Khan Sheikhoun by the toxic gas.

Syria's Foreign Minister Walid al-Moallem denied at a press conference Thursday that the Syrian army fired toxic gas on Khan Sheikhoun town in Idlib province.

The minister said the army struck an arm depot which belongs to the al-Qaida-linked Nusra Front, adding that the depot contained chemical materials the terrorists were bringing in from Iraq.