Ahmet Davutoglu, the Turkish foreign minister, has met Syrian President Bashar al-Assad in Damascus, as Syrian security forces continued their military assault against protesters across the country.
Assad told Turkey's foreign minister on Tuesday that Damascus will "not relent in pursuing terrorist groups", Syrian state news agency said.
Davutoglu was to deliver a "strong message" to the president during his visit to the Syrian capital, Turkey said ahead of the visit.
Turkey, formerly Syria's close ally and trade partner, has grown increasingly alarmed by the security forces' use of force in the country's anti-government protests, which activists say has claimed about 2,000 lives.
As Davutoglu met Assad and the Syrian foreign minister, Walid al-Muallem, the army intensified its assault on several towns in the east of the country and in the northern Idlib province, which borders Turkey.
A rights group said 17 civilians were killed in the eastern city of Deir ez-Zor, and two others in Idlib province.
"At least 15 people were killed in different parts of Deir ez-Zor which has been raided by tanks and vehicles mounted with machine guns," the UK-based Syrian Observatory for Human Rights (SCHR) said in a statement. quoting activists at the scene.
"A woman and a young man shot [earlier in the day] died of their wounds."
A resident said armoured vehicles had been shelling the al-Hawiqa district heavily.
"Private hospitals are closed and people are afraid to send the wounded to state facilities because they are infested with secret police," the resident told Reuters news agency.
He said at least 65 people had been killed since tanks and armoured vehicles entered the provincial capital on Sunday.
The SCHR said around a dozen tanks and other armoured vehicles had attacked the Binnish and Sirmeen areas of Idlib.
Asked why Binnish was stormed, a resident who had fled the town told Reuters: "The whole town has been joining in night rallies after Ramadan prayers."
The Local Co-ordination Committees said the town of Sirmeen was attacked from three sides, with troops carrying out house raids and arbitrary arrests.
Tanks were also deployed in and around the city of Idlib, following big demonstrations there, the activists said.
Hama deaths reported
Up to five civilians were later also during raids on villages around the besieged city of Hama on Tuesday, local activists said.
The Syrian Revolution Co-ordinating Union said five bodies had been taken to the Jwash hospital in the town of Tibet al-Imam north of Hama, including two girls from the same family, six-year old Afra Mahmoud al-Kannas and 11-year old Sana Ahmad al-Kannas.
In-depth coverage of escalating violence across Syria
Al Jazeera could not independently verify the reports since most foreign journalists have been barred from entering Syria.
The Syrian Observatory says more than 2,050 people, including almost 400 members of the security forces, have been killed since the uprising began.
Envoys from India, Brazil and South Africa are going to Damascus to press Assad to end the violent crackdown on a five-month old uprising.
India's UN ambassador Hardeep Singh Puri told reporters the three countries would be "calling for restraint, abjuring violence, [and] promoting reform, taking into account the democratic aspirations of the people.''
Officials said country's representatives were to meet "high-level'' Syrians on Wednesday.
Assad's government disputes the toll and blames a foreign conspiracy for the unrest. But those claims have been dismissed by most of the international community, with world leaders ramping up its condemnation of the security forces' actions in recent days.
Lebanese and Syrians living in Beirut rallied in solidarity with the Syrian people on Monday
Saudi Arabia, Kuwait and Bahrain on Monday recalled their ambassadors from Damascus amid mounting pressure from the Arab world.
Qatar withdrew its ambassador from Damascus and closed its embassy in July after Assad loyalists attacked the embassy compound amid protests against Doha-based Al Jazeera's coverage of the uprising.
Meanwhile, Assad replaced his defence minister, Ali Habib, on Monday with illness cited as the official reason.
State television reported that the Christian chief of staff, General Daoud Rajha, was to take up the post.