|Earlier this week, the UN failed to pass a resolution condemning President Assad's crackdown on protesters [Reuters]
The United Nations has raised its tally of people killed during seven months of unrest in Syria to more than 2,900 - an increase of 200 people since the beginning of September.
Rupert Colville, a spokesman for the UN High Commissioner for Human Rights, said on Thursday that the figure was based on "reliable sources" inside and outside the country.
He also said that the names of the dead had all been confirmed and likely included some members of the security forces.
Twelve people were killed in clashes between soldiers and deserters in villages of Idlib province in northwest Syria on Thursday, a human rights group said.
"Seven soldiers and five deserters were killed in the clashes in villages west of Jabal al-Zawiya," the Britain-based Syrian Observatory for Human Rights said, adding that dozens were wounded.
Similar clashes earlier in the week between Syrian troops and deserters - who defected after refusing to fire on anti-government protesters - left four people dead near the Turkish border, rights activists said.
A army officer who has taken refuge in Turkey, Colonel Riad al-Asaad, claims to have established an opposition armed force called the "Syrian Free Army", but its strength and numbers are unknown.
In a separate incident, Syrian troops entered Lebanese territory on Thursday and shot dead a Syrian living in a remote border area of the eastern Bekaa region, a security official told AFP news agency.
A Lebanese government official, speaking on condition of anonymity, confirmed the incident and said it was unclear why al-Khatib was targeted or how he was killed.
Earlier this week, Syrian tanks entered the same region in a brief incursion that raised fears of the revolt against the government in Damascus spilling over into Lebanon.
Analysts have warned that the unrest in Syria is becoming increasingly armed in response to the relentless gunning down by security forces of protesters in major cities and towns.
Meanwhile, Germany's foreign ministry on Thursday summoned Syria's ambassador to Berlin to complain about what it deemed a disparaging comment by the Syrian envoy during a UN Security Council vote this week on President Bashar al-Assad's crackdown.
In-depth coverage of escalating violence across Syria
After Tuesday's Security Council vote, at which permanent members Russia and China vetoed the European-drafted resolution condemning Syria for its bloody crackdown on protesters, Syrian envoy Bashar Ja'afari told reporters: "Here Germany comes, the third musketeer, Germany who persecuted the Jews in Europe, is now trying to show itself as an honest broker of a very deceiving and cheating draft resolution on Syria."
Germany's foreign ministry responded in a statement: "The Syrian ambassador to the UN expressed himself in a completely unacceptable way at the end of the meeting of the UN Security Council on the Syria resolution."
The German foreign ministry also said it had made clear that spying and exerting pressure on members of the Syrian opposition in Germany was "in no way acceptable".
The European Union is preparing to target a Syrian commercial bank in fresh sanctions to be announced in the coming days, EU diplomats in Brussels said on Thursday.