Bombardments by the Syrian regime killed six civilians in northwest Syria Monday, hours after US
President Donald Trump urged Damascus and its allies to "stop bombing the hell" out of the jihadist-held region.
Trump's call came after Washington's Israeli ally carried out a series of strikes against Syria over the weekend, leaving at least 15 dead among pro-government forces, according to the Syrian Observatory for Human Rights.
The bombardment by Damascus and regime ally Russia of Idlib province and neighboring areas has killed more than 300 people and displaced thousands since late April, according to the Britain-based war monitor.
The violence, which comes despite a truce deal brokered by Moscow and Ankara in September, has raised fears of a humanitarian catastrophe on a scale yet unseen in Syria's eight-year conflict, which has already claimed more than 370,000 lives.
The Kremlin insisted Monday that the Russian army was only targeting "terrorists" in Syria's Idlib region, which is controlled by Hayat Tahrir al-Sham, a group dominated by former members of Al-Qaeda's Syria affiliate.
It accused them of firing at civilians and Moscow's troops.
"Terrorist fire in Idlib is of course unacceptable," Kremlin spokesman Dmitry Peskov said. "Measures are being taken to neutralize such firing positions."
The comments came in response to a Tweet by Trump on Sunday calling for an end to the bombing on the jihadist-dominated enclave, a large area which is home to almost three million people.
"Hearing word that Russia, Syria and, to a lesser extent, Iran, are bombing the hell out of Idlib Province in Syria, and indiscriminately killing many innocent civilians," Trump said.
"The World is watching this butchery. What is the purpose, what will it get you? STOP!"
But, the aerial bombardment on Monday did not relent.
According to the Observatory, at least four civilians were killed in regime strikes on the town of Maarat al-Numan.
Another civilian was killed in the nearby town of Heish, while a sixth was killed by rocket fire on a village in the neighboring province of Hama, it said.
Human Rights Watch on Monday accused the Syrian regime and its ally Russia of using "internationally banned and other indiscriminate weapons in unlawful attacks on civilians in northwest Syria in recent weeks."
It said they "used banned cluster munitions and incendiary weapons... along with large air-dropped explosive weapons with wide-area effects, including 'barrel bombs.'"
Analysts predict that President Bashar al-Assad and his allies will continue to chip away at the area, but not unleash a major assault that would create chaos on Turkey's doorstep.
In recent weeks, jihadists and pro-government have engaged in fierce battles over positions on the fringes of the enclave.
On Monday, the regime tried advance against jihadists in the north-east of Latakia province.
According to the Observatory, the clashes killed 12 pro-regime fighters and seven jihadists.
The latest violence in Syria's jihadist-held northwest comes amid soaring tensions between Syria and neighboring Israel.
Syria accused Israel of targeting an airbase in Homs province overnight, reportedly killing five people, just hours after carrying out raids on military and intelligence posts south of Damascus that killed 10.
"Our air defenses thwarted an Israeli aggression and destroyed two of the rockets that targeted the T-4 airbase," a military source told state news agency SANA.
The remaining rockets "killed one soldier, wounded two others, and damaged an arms warehouse," the source added.
The Britain-based Observatory reported five killed, including one Syrian soldier, adding that a rocket warehouse was destroyed.
In addition to the Syrian army, Iranian fighters and Hezbollah paramilitary forces are also stationed at the airbase, according to the monitor.
Israel did not claim the attack, and a spokeswoman for the Israeli army told AFP: "We do not comment on foreign reports."
But hours earlier, Israel said it had carried out strikes in the province of Quneitra, after two rockets were fired into Israel from its neighbor late Saturday.
The Observatory said 10 people were killed, including Syrian soldiers and foreign fighters.