US and Arab warplanes hammered Islamic State militants in eastern Syria early Tuesday, opening a new front in the fight against the jihadist group, defense officials said.

Syrian activists reported some 20 strikes against IS targets in the jihadists’ stronghold of Raqa province.

“The international coalition struck IS positions, bases and checkpoints in Raqa city, and near the towns of Tabqa, Ain Eissa and Tal Abyad, killing jihadists,” the Syrian Observatory for Human Rights said

Bahrain, Jordan, Qatar, Saudi Arabia and the United Arab Emirates took part in the bombing raids, US media reported, in an extraordinary show of Arab solidarity against the IS group that has rampaged through Syria and Iraq.

A US defense official, who spoke on condition of anonymity, confirmed to AFP that Arab “partners” joined the bombing runs but did not say which countries were involved.

F-22 fighter jets: involved in the strikes

The US-led air assault in Syria marks a turning point in the war against the IS group, as the administration of US President Barack Obama had long been reluctant to intervene in Syria’s raging civil war.

But Washington concluded it had to act and convinced Arab allies to join in, amid fears IS fighters could wreak havoc across the region and eventually stage terror attacks in Europe or the United States if left unchecked.

“I can confirm that US military and partner nation forces are undertaking military action against ISIL (Islamic State group) terrorists in Syria using a mix of fighter, bomber and Tomahawk Land Attack Missiles,” Pentagon spokesman Rear Admiral John Kirby said in a statement.

The decision to conduct the air strikes was undertaken on Monday by the head of US Central Command, General Lloyd Austin, “under authorization granted him by the commander in chief,” Kirby said.

“We will provide more details later as operationally appropriate.”

The strikes focused on IS positions in Raqa, a stronghold for the Sunni extremists, as well as targets along the Iraq-Syria border, according to a second Pentagon official, who spoke on condition of anonymity.

US F-22 fighter jets, America’s most sophisticated warplane, were scheduled to take part in the raids as well — the first combat mission for the costly aircraft, the second official said.

Along with “ongoing” air raids, the US military fired Tomahawk cruise missiles from warships in the Gulf and Red Sea, the official said.

A senior White House official told AFP that Obama was “being updated on the operation” in Syria.

US media said the president had spoken to Congressional leaders about the strikes.