Air strikes, believed to have been Russian, have killed 69 civilians in recent days, the Syrian Observatory for Human Rights reports
The Syrian government's powerful Lebanese ally Hezbollah has declared victory in the Syrian war, dismissing remaining fighting as "scattered battles", a pro-Hezbollah newspaper reported on Tuesday.
The comments by Hezbollah leader Sayyed Hassan Nasrallah mark one of the most confident assessments yet by the government side as it regains swathes of territory in eastern Syria in a rapid advance against the Islamic State group.
Referring to President Bashar al-Assad's opponents, Nasrallah said "the path of the other project has failed and wants to negotiate for some gains", the al-Akhbar newspaper cited him saying at a religious gathering.
"We have won in the war (in Syria)... and what remains are scattered battles," said Nasrallah, whose Iran-backed group has sent thousands of fighters to Syria to support Assad.
We have won in the war (in Syria)... and what remains are scattered battles
- Hezbollah leader Sayyed Hassan Nasrallah
A source familiar with the contents of Nasrallah's speech confirmed al-Akhbar's report.
The war is now focused on the east of the country where air strikes likely carried out by Russian warplanes killed 69 people in Deir Ezzor since Saturday, the Syrian Observatory for Human Rights said on Tuesday.
Backed by Russia and Iran, Assad has crushed numerous pockets of rebel-held territory in the western Syrian cities of Aleppo, Homs and Damascus over the last year, and he appears militarily unassailable in the six-year-long conflict.
On Tuesday, the head of the Russian troops' headquarters in Syria, Alexander Lapin, said that the Syrian army has cleared 85 percent of the country's area from militants, Russian news agencies reported.
IS fighters are still in control of around 27,000 square km of Syria's territory, he said.
Government manpower freed up by ceasefires
Ceasefires brokered by Russia, Turkey, Iran and the United States in remaining rebel-held areas of western Syria have freed up manpower on the government side, helping its advance east into the oil-rich province of Deir Ezzor.
The eastward march to Deir Ezzor, unthinkable two years ago when Assad seemed in danger, has underlined his ever more confident position and the dilemma facing Western governments that still want him to leave power in a negotiated transition.
Syrian troops advancing against IS in Deir Ezzor last week (AFP)
Government forces last week reached Deir Ezzor city, the provincial capital on the Euphrates River, breaking an IS siege of a government-held enclave and a nearby air base.
In a televised speech last month, Assad said there were signs of victory in the war, but that the battle continued.
US-backed militia fighting under the banner of the Syrian Democratic Forces (SDF) have in recent days launched a separate offensive against Islamic State in Deir Ezzor province.
The SDF, which is dominated by the Kurdish YPG militia, is also waging a campaign to capture Raqqa city from IS. It has avoided conflict with the Syrian government.
Russian airstrikes kill 69 civilians
Russian air strikes have killed 69 people in Deir Ezzor since Saturday, the Syrian Observatory for Human Rights said on Tuesday.
The Russian defence ministry did not immediately respond to a Reuters request for comment on the report by the Britain-based monitoring group.
The Observatory, which identified the victims as civilians, said the air strikes had hit civilian encampments on the western bank of the Euphrates, and vessels crossing the river to the eastern side.