It comes amid an increasingly violent and fiery battle between US and Iranian forces in Syria (Photo: CBS)

The US launched a nighttime airstrike on Syria after a suspected Iranian drone killed an American.

A US contractor was killed and five US military personnel injured when a self-destructing drone struck a base maintenance facility yesterday.

U.S. intelligence analysts said the drone was “of Iranian origin,” the Pentagon said of the incident, which occurred around 1:40 p.m. near Hasaka.

As relations between Washington and Tehran become tense, a new wave of airstrikes has reportedly hit parts of eastern Syria today.

It came after Iranian-backed militants tonight used missiles against another base hosting US personnel in Syria’s Conoco gas field.

Syrian opposition activist groups said the targeted sites were being used by groups affiliated with Iran’s Islamic Revolutionary Guard Corps (IRGC).

The three sites were in Deir Ez-Zor, a province bordering Iraq and dotted with oil fields.

Activist group Deir Ezzor 24 said four people were killed and several others injured in the attacks.

The Syrian Observatory for Human Rights, a group that monitors the war in Syria, estimated the death toll from US attacks to be even higher, at 11 Iranian-backed militants.

Six of them in a weapons depot in the city of Deir el-Zour and five in military posts near Mayadeen and Boukamal.

The head of the observatory, Rami Abdurrahman, said earlier today that three rockets were fired at the al-Omar oil field in Deir el-Zour, where US troops are stationed.

It is unclear whether US fighter jets carried out the attacks in Deir ez-Zor.

Defense Secretary Lloyd Austin said the retaliatory action was ordered by US President Joe Biden.

In a statement, Austin said U.S. intelligence had determined the drone was of Iranian origin, though he failed to provide any evidence.

“The airstrikes were carried out in response to today’s attack and a series of recent attacks on coalition forces in Syria by IRGC-affiliated groups,” he said.

A US defense official claimed that the US strikes were carried out by F-15E fighter jets, which hit three areas near Deir el-Zour.

Iran is deploying proxy forces across the Middle East to counter the US, which has stationed troops in northeastern Syria since 2015.