Four Turkish soldiers were killed and 15 wounded in clashes with Islamic State (IS) militants in Syria on Wednesday as the military faced increasing resistance from the extremists in a battle to take a key town, state media said.
The IS-held town of Al Bab, 25 kilometres (15 miles) from the Turkish border, has become the main target of the army's more than three-month campaign inside Syria in support of pro-Ankara Syrian rebels.
One of the 15 wounded was in a serious condition, the Anadolu news agency reported. The corpses of the four dead soldiers were flown to Gaziantep in Turkey.
The Amaq news agency, affiliated to IS, said a suicide attack was carried out against the Syrian rebels and Turkish troops west of Al Bab, without giving further details.
The Turkish air force meanwhile struck 47 IS targets around Al Bab, killing more than 45 Islamist militants , Anadolu said. It was not immediately possible to confirm the figures.
After the lightning speed of the earlier campaign that saw the border town of Jarabulus taken on the first day of the offensive, the Turkish army has suffered increasing casualties in the fight for Al Bab.
Around two dozen Turkish soldiers are believed to have lost their lives since Ankara launched its operation Euphrates Shield in August, with most of the deaths blamed on IS attacks.