Turkish military hits Daesh targets in the northern Syrian town. Separately, regime air strikes killed at least four people and wounded another 15 in a rebel-held district of Damascus, days before Geneva peace talks.
The Turkish military hit 18 Daesh targets in al-Bab, Syria on Sunday, the army said on Monday, as Turkey-backed opposition forces advanced in the northern town.
The military said it had "neutralized" (killed, captured or wounded) 27 Daesh militants in the latest fighting. It said air strikes had destroyed at least 16 buildings, a weaponry depot and a car carrying weapons.
Turkey launched Operation Euphrates Shield in August 2016 to target Daesh on the Syrian side of the border. It is also targeting the YPG, which it considers a terrorist group. The US-backed YPG is fighting Daesh and the regime of Bashar al-Assad.
Turkey wants to set up a 5,000 square kilometre safe zone in Syria to alleviate the Syrian refugee crisis.
Daesh clinging on in al-Bab
Last week, Turkey's military said it was close to taking al-Bab from Daesh, but a war monitor said the militants still controlled 90 percent of the town.
Al-Bab is a Daesh stronghold 30 kilometres (20 miles) from the Turkish border. It has been a prime target of Euphrates Shield.
Taking control of the town would allow Turkish forces to press on towards Raqqa, Daesh's de facto capital in Syria.
Daesh-held areas straddle Syria and Iraq. On the weekend the Iraqi government launched a campaign to clean Daesh out of Mosul, its last stronghold in Iraq. Losing Raqqa and Mosul would significantly deplete Daesh's resources.
Bombing near Damascus
Syrian regime forces on Monday escalated their bombing campaign around Damascus, raining shells down on rebel territory and sending out a "bloody message" just days before renewed peace talks in Geneva.
"Regime air strikes killed four people and wounded another 15 in escalation on Barzeh," a northern rebel-held district of Damascus, the Syrian Observatory for Human Rights and activists on the ground said.
The Britain-based monitor said rockets also hit the northeastern opposition-controlled neighbourhood of Qabun overnight and into Monday morning. Rebels and regime forces reached a local ceasefire deal in Qabun in 2014, but violence has built up in the neighbourhood since last week. At least 16 people were killed on Saturday in government rocket fire on a funeral in Qabun, according to the Observatory.
"This is the third day of bombardment — rockets, artillery, mortars, and air strikes," said media activist Hamza Abbas, speaking to AFP via internet from Qabun, where he said he could hear non-stop shelling.
"The bombardment is targeting three neighbourhoods — Qabun, Barzeh, and Tishreen," Abbas said.
The escalation comes as representatives from the opposition and the Assad regime prepare to meet in Geneva on Thursday in their latest bid to end the six-year war.