The Syrian Observatory for Human Rights, a monitoring group, said the strikes were on an office and a vehicle in Idlib province in northwest Syria, where last week the group routed Western-backed Syrian rebels.
Residents said one strike targeted a car used by Nusra commanders, near an internet cafe in the Nusra-controlled town of Sarmada close to the Turkish border.
A rebel from another Western-backed group operating in northern Syria confirmed the air strikes on the Nusra Front and hardline Islamist group Ahrar al-Sham near the border with Turkey, and said they took place at around 1 a.m.
“The strength of strikes and their accuracy confirms that they were carried out by the alliance,” the rebel said, speaking on condition of anonymity.
The Nusra Front vehicle struck in the attack had been carrying ammunition, he said.
In neighboring Harem, residents said at least four children had been killed and dozens injured in an attack they believed was launched by the coalition.
The Observatory also reported the first air strikes against Ahrar al-Sham.
Residents around the rebel-held Bab al-Hawa border crossing, a strategic gateway to Turkey, said a missile flattened the group’s headquarters nearby and killed Abu al-Nasr, the head of its arms procurement division.
Rami Abdulrahman, head of the Observatory, said it marked the second time the Nusra Front had been hit in the U.S.-led campaign. The first was on Sept. 23, the first day of U.S. air strikes in Syria, which are part of Washington’s strategy to “degrade and destroy” Islamic State.
Nusra, which has been trying with allies to remove its name from the U.N. terrorist list, was taken by surprise when coalition warplanes bombed several of its positions then.
Several commanders are believed to have been killed in the September strikes, including Kuwaiti-born Mohsin al-Fadhli — also known as Abu Asmaa al-Jazrawi — reputedly a former member of Osama bin Laden’s inner circle.
Nusra Front last week seized control of areas of Idlib province from Western-backed rebel leader Jamal Maarouf, head of the Syria Revolutionaries’ Front in northern Syria, confiscating its weapons. It also took positions from the Hazzm Movement, another recipient of Arab and Western support.
Maarouf, whose group is one of the biggest non-Islamist rebel formations, said in a video statement his group had abandoned villages only to avoid civilian casualties.
The retreat marked a big blow to the non-Islamist opponents of President Bashar al-Assad, who have generally struggled against better armed and equipped Islamist groups including Nusra Front and Islamic State.
The United States is planning to expand military support to what it describes as the moderate opposition to Assad as part of its strategy against Islamic State in Syria.
Nusra Front was once seen as the strongest insurgent group in Syria but has been eclipsed this year by Islamic State, which has seized wide areas of Syria and Iraq.