Despite Saturday's errant U.S. airstrike that Russia claims killed 62 Syrian troops, the Syrian government is upping the battle against Islamic State fighters in the eastern province of Deir Ezzor.
Soon after the smoke cleared from the U.S. raid over the weekend, at least 1,000 additional Syrian soldiers were deployed to the besieged desert city, which has strategic significance for both the regime and the Islamic State group.
Syrian troops counter-attacked Monday and Tuesday at one neighborhood near a mountain area that IS extremists temporarily controlled following the U.S. strike. Social media reports say several IS fighters were killed as the regime regained control of the area.
The offensive came as the Syrian government unilaterally ended a truce in the Syria war, even as U.S. and Russian officials sought to keep the truce alive.
"Deir Ezzor presents an opportunity for the [Syrian] regime to show its effectiveness after the cease-fire has failed," said Daryous Darwish, a Syrian affairs analyst who lives in exile in France.
City under siege
Deir Ezzor is a virtual island surrounded by hundreds of square kilometers of desert, not far from the Iraq border. IS has controlled nearly the entire province since mid-2014, except for small pockets of the city that remained in the hands of Syrian government forces.
"It is located in the heart of [Islamic State's} so-called caliphate, connecting Syria with Iraq," Darwish said.
Due to continued fighting, more than 250,000 residents in different parts of the city have been under siege for months, according to the United Nations and Syrian rights groups. The area sees nearly daily bombardments, both from Russian warplanes supporting the Damascus regime and from planes of the U.S-led coalition targeting IS strongholds.
Targeting oil fields
IS fighters control most of the oil fields in Deir Ezzor, and oil production has been a major source of revenue for the extremists. U.S.-led airstrikes mainly target the oil facilities and Islamic State's supply routes.
"At least 30 percent of oil and natural gas production in Syria comes from Deir Ezzor," said Musallam Talas, a Syrian economist who teaches at the Mardin Artuklu University in Turkey.
IS has been increasing its presence in eastern and central Syria, after having been routed from much of northern Syria by Turkey-backed rebels and U.S.-backed Kurdish forces.
FILE - A still image, taken from video footage and released by Russia's Defence Ministry on Aug. 18, 2016, shows a Russian Sukhoi Su-34 fighter-bomber based at Iran's Hamadan air base, dropping bombs in the Syrian province of Deir Ezzor.
Troops fighting IS expect the next big offensive will try to oust the extremists from their remaining major strongholds in two big cities, Deir Ezzor and Raqqa.
Russian airstrikes key
Observers say Syrian troops are hampered in their fight against IS because they must travel a long way from government strongholds near Damascus. The Syrian regime said the weekend strike by U.S. jets against Syrian troops was a setback, but that continuing Russian air support for government forces is crucial.
"That effectiveness can only occur with surgical Russian airstrikes against [Islamic State]," said analyst Darwish.
The Assad government's attempts to expand its holdings in Deir Ezzor are limited, because manpower and supplies must come through the city's embattled airfield, according to the Syrian Observatory for Human Rights.
FILE - A man walks past a banner reading "Pray for Deir Ezzor" at the migrant camp known as the "Jungle" in Calais, France, Dec. 7, 2015.
Many residents in Deir Ezzor have fled IS tyranny to regime-held areas. But aid groups have no access to assist them because of the fighting, the Observatory told VOA. Most people survive on a few rations and some bread provided by the government.
"After six days of outage, drinking water is now running again in [government-held] neighborhoods of al-Joura, al-Qusour and al-Mouazafeen," said Deir Ezzor 24, a website that reports news on the city.