Warring sides continue fighting in Syria as representatives of some of them prepare to meet in Geneva for the next round of peace talks. In Turkey, a soldier was slain by a sniper firing across the border from Syria.
The Syrian regime is sending reinforcements to face a major rebel offensive in Hama province, a regime military source said on Wednesday, as rebels pressed an attack in a western area critically important to regime leader Bashar al Assad.
Syrian rebels said they launched a new offensive on Tuesday near the city of Hama in the central part of western Syria.
The rebels attacked regime positions in the town of Soran and the village of Maardas, gaining control over parts of them, a monitor of Syria's civil war said.
The Tahrir al-Sham group said on a social media feed that it had carried out two suicide car bomb attacks close to Soran in the countryside north of Hama at the start of the assault.
"The battle of Hama has begun, God be thanked," the group said in a posting on a Telegram channel it uses.
Tahrir al-Sham is an alliance of Syrian rebel groups that also includes former Nusra Front, which was born out of al Qaeda. A fragile ceasefire in place in Syria brokered by Turkey and Russia excludes Tahrir al-Sham.
A pro-regime media unit run by Hezbollah, an Iran-backed ally of Assad, said that fighting continued with the rebels who attacked its positions north of Hama.
The Syrian Observatory for Human Rights (SOHR), a London-based war monitor, said explosions were heard in that area and that intense clashes were ongoing.
The rebels had gained control over several positions in the area around Soran and in Maardas just south of it, SOHR said. But Hezbollah media said the rebels had not gained control over either Soran or Maardas.
The assault spearheaded by rebels follows two big attacks on Assad's seat of power in Damascus in recent days, showing the lingering threat posed by the opposition to Assad, even as his military and their allies gain the upper hand in the war.
TRT World's Shamim Chowdhury is in Gaziantep on Turkey's border with Syria and has this summary of the latest fighting.
The UN on Tuesday urged those attending this week's Syria peace talks to engage "substantively and proactively."
The next round of the negotiations will be held in Geneva on Thursday.
"All invitees who had already attended the previous round of talks in February 2017 have confirmed their participation," Staffan de Mistura, the UN special envoy for Syria said.
Previous attendees were delegates for the Syrian regime, headed by Bashar al-Ja'afari, and representatives of the opposition, led by Nasr Hariri from the High Negotiations Committee.
De Mistura visited Saudi Arabia's capital Riyadh over the weekend, his office said, and he is due to travel to Moscow and Ankara before returning to Geneva on Thursday.
Thursday's agenda will focus on governance, constitutional issues, elections, security and confidence-building.
The last round of talks began on February 23 and ended on March 4 without any clear result.
Turkish soldier slain
The Turkish military said on Wednesday one of its soldiers was killed by a sniper shot from across the border in a YPG-controlled part of northwestern Syria.
The soldier was in the Turkish border province of Hatay. The shooting came two days after the YPG, considered by Turkey to be a terrrorist organisation, claimed Russia was setting up a military base in Syria bordering Hatay and would help train its fighters. Russia denied that claim.
The Turkish military said it had returned fire after the soldier was killed.