WASHINGTON >> Fighter jets deployed by Arab allies launched a series of airstrikes in Syria in the early hours Tuesday, as the United Arab Emirates returned to combat missions against the Islamic State for the first time since December, and Jordan separately continued its escalation of strikes against Sunni militants.

A squadron of Emirati F-16 fighters struck Islamic State targets in Syria and returned safely to base in Jordan, the UAE armed forces announced.

Emirati officials said the concerns that prompted them to suspend combat missions — that the U.S. Central Command had not deployed sufficient assets closer to the battlefield to rescue downed pilots — had now been addressed.

Jordan also stepped up its raids; Mansour Jaboor, the head of Jordan’s air force, said that Jordan had carried out 56 airstrikes against the Islamic State in recent days, as King Abdullah of Jordan continued to make good on his promise to avenge the immolation of a Jordanian pilot by the militant Sunni group.

Bahrain’s ruler issued a public statement that his country was ready to assist Jordan in the fight against the Islamic State, according to a statement released by Jordan’s palace.

Jordanian officials denied reports of a large movement of ground troops toward the Iraqi border, and asked journalists to "be careful and to abide by the information that is issued by the concerned agencies and the Jordan armed forces."

"There is no talk about a ground war," one official said, speaking on the condition of anonymity in accordance with government protocol. "We will not be reluctant to face this criminal gang in any place in the world to defend our religion, our nation, and the future of our country and our sons.

But in other ways, since last week when the video of the pilot being burned alive was released, Abdullah has been stepping up raids on the Islamic State — or at least increasingly publicizing them — and working to increase Arab participation in the coalition against the group.

The public announcements of increased Arab participation in the fight against the Islamic State is welcome news for the Obama administration, which has sought to characterize the fight against the Sunni militants as an international coalition with Arab participation.

In an interview on Tuesday, Yousef al-Otaiba, the United Arab Emirates ambassador to the United States, said that the Emirates was "fully committed" to defeating the Islamic State "and will not back down."