In Damascus, mortar fire hit the neighborhood of the Russian Embassy, killing one Syrian and wounding nine, including members of the embassy's guard corps, according to the Russian Foreign Ministry.
Rebels fighting to topple President Bashar Assad have fired mortar shells on the capital with increasing regularity in the past few weeks. A statement said the embassy building sustained only minor damage.
The fighting near the border with Lebanon is part of a fierce offensive north of the capital that has seen several rebel strongholds fall into government hands in recent weeks.
President Bashar Assad's forces launched the push into the rugged Qalamoun region along the border in order to cut off rebel supply routes and stem the flow of fighters. The fighting has forced thousands of Syrians to flee to neighboring Lebanon.
Militants from Lebanon's Iranian-backed Hezbollah group openly joined the war on the side of government forces in May, tipping the scales against the rebels fighting for Assad's overthrow.
A Syrian army statement said troops have fully seized control of Deir Attiyeh and pledged to continue its pursuit of "terrorists" all over the country until full victory.
The Britain-based Syrian Observatory for Human Rights confirmed government forces are almost in full control of Deir Attiyeh, whose population is nearly a third Christian. An activist in the area who uses the name Amer al-Qalamouni said troops captured the town after members of the radical Islamic State of Iraq and the Levant militia withdrew.
"They were very fierce battles and conditions for civilians there are dismal," al-Qalamouni said.
The Observatory and al-Qalamouni said five doctors and four nurses were killed in the clashes over the past two days at Deir Attiyeh's main hospital.
SANA quoted Syria's Health Minister Saeed al-Nayef as saying "terrorists committed a massacre" by killing five doctors, five nurses and two ambulance drivers in Deir Attiyeh.
In Lebanon, an official close to Hezbollah said a nephew of Lebanese Minister of Agriculture Hussein Haj was killed in Syria this week while fighting in the Qalamoun region. The official spoke on condition of anonymity in line with regulations.
Haj is a senior Hezbollah official.
SANA said that the army killed many fighters in Deir Attiyeh including Saudis, and discovered underground tunnels. Saudi Arabia has been one of the strongest backers of the Syrian opposition.
The fighting has led to the closure of the highway that links Damascus with the central city of Homs, home to one of Syria's two oil refineries. The road closure has caused a fuel shortage in the capital.
Fighting is now concentrated around the rebel-held town of Nabek, just south of Deir Attiyeh, according to al-Qalamouni and the Lebanon-based Al-Mayadeen TV, which has a reporter embedded with Syrian troops in the area.
Also Thursday, the Western-backed Syrian National Coalition, Syria's main opposition group in exile, criticized the Syrian government for saying it will participate in U.N.-sponsored peace talks aimed at ending the country's civil war, but that it is not going to the conference to hand over power.
"It has become evident that the Assad regime is trying to cover its war on the Syrian people, whilst maintaining a pretense of co-operation with the international community," the coalition said.
The Jan. 22 meeting in Geneva, which would be the first face-to-face talks between Assad's government and its opponents since the Syrian war began, has raised hopes for a negotiated end to fighting that activists say has killed more than 120,000 people.
Both sides have said they will attend the Geneva talks.
Mroue reported from Beirut. Associated Press writer Jim Heintz in Moscow contributed to this report.