BEIRUT — Turkey launched a new incursion into Syria on Saturday, dispatching additional tanks and troops across the border to support Syrian rebels fighting the Islamic State, expanding the scope and reach of its 10-day-old military intervention.

The additional Turkish forces crossed the border into the rebel-controlled town of Al-Rai, which rebels seized from the Islamic State last week but have since struggled to secure, according to the official Turkish news agency Anadolu.

Al-Rai is 34 miles west of Jarabulus, the border town that was the original target of the initial Aug. 24 intervention, code named Operation Euphrates Shield.

The Islamic State still controls the territory lying between the two towns, and the extra force, including at least 20 tanks and at least half a dozen armored vehicles, is intended to intensify the Turkish effort to push the Islamic State back from Turkey’s border.

The expansion of the intervention will bring additional pressure to bear on the weakening Islamic State, but also further complicates the battlefield in northern Syria, where the United States is backing rival efforts by its allies to inflict defeat on the militants.

Taking territory from the Islamic State in areas along the Turkish border also prevents Syria’s Kurds from controlling them, and Turkey has made no secret of the fact that halting Kurdish expansionism is as much a goal of the intervention as battling the Islamic State.

Turkish-backed rebels have already clashed on several occasions with Kurdish and Arab fighters as they pressed south of Jarablus toward Manbij, a town liberated by a Kurdish-led force from the Islamic State with US support late last month.

After securing the border area between Jarablus and Al-Rai, the next target of the Turkish-led operation will be to control Al-Bab, a major Islamic State stronghold farther south, and well away from the border, according to the Daily Sabah, a government-controlled newspaper.

The Kurds have also identified Al-Bab as their next target in the Islamic State fight.

Saturday’s intervention in Al-Rai was backed by Turkish warplanes and helped the Free Syrian Army-affiliated rebels already fighting in the area capture two more villages from the Islamic State, the Anadolu agency said.

The agency used Al-Rai’s Turkish name, Cobanbey, in its reports on operation, in a reminder that until the 1920s, Turkey ruled the areas of Syria in which it is now intervening.

The Syrian war has spurred the most serious displacement crisis since World War II, creating 4.3 million refugees, at least half of whom are children.

A year ago, the war’s toll on children was painfully underscored by the image of a little boy lying facedown on a Turkish beach. In death, Alan Kurdi became a symbol of Syria’s ‘‘lost generation.’’

Children are thought to account for about 20 percent of the almost half-million Syrians who have died during the course of the five-year war.

According to UNICEF, an additional 8.4 million children — more than 80 percent of the country’s youth population — have been affected in some way, either living with violence in Syria or fleeing abroad.

The Syrian military has repeatedly placed rebel-held areas under blockade, limiting the ability of humanitarian groups to get aid to besieged civilians. Across rebel-held parts of the country, repeated strikes on hospitals also have severely limited access to health care.

Marking the anniversary of Alan Kurdi’s death last week, Amnesty International Secretary General Salil Shetty called on wealthier countries to do more to assist Syrian children.

‘‘Until wealthy countries take more responsibility for the crisis unfolding before them, and take in a fairer share of the people fleeing war and persecution, they will be condemning thousands more children to risk their lives in desperate journeys or being trapped in refugee camps with no hope for the future,’’ Shetty said.

Photographs of the child were shared millions of times, prompting fierce debate over global responsibility for Syria’s refugee crisis.

But a powerful wave of right-wing populism across Europe and the United States, as well as repeated Islamic State-linked attacks across both continents, appear to have reversed what small concessions the little boy’s death inspired.

The United States admitted its 10,000th Syrian refugee last week in a resettlement program announced by President Obama last fall, reaching a target set under pressure from European and other countries struggling to cope with the crisis.

But the United States, like Britain, has been criticized for focusing most of its humanitarian aid on improving services for refugees who remain in the Middle East instead of sharing a burden by accepting more refugees.