The officials said a woman was killed when a shell hit her home in the Wadi Khaled area of northeast Lebanon, and five people were wounded. Another shell hit the nearby village of al-Hisheh, they said, killing an 8-year-old boy and wounding his father and four children. (Reuters, quoting residents, said three other Lebanese civilians were killed in the shelling.)

The security officials spoke on the condition of anonymity because of police rules.

Sixteen months of bloodshed in Syria have raised fears that the unrest will cross over into Lebanon, which has extensive sectarian and political ties to its eastern neighbor. There have been several instances of cross-border shelling, as well as deadly clashes between Lebanese factions that sympathize with either the government of President Bashar al-Assad of Syria or opposition forces.

In Syria itself, opposition activists reported fierce government offensives to try to retake rebellious areas outside the northern city of Aleppo and near the capital, Damascus.

The Syrian Observatory for Human Rights, which is based in Britain and relies on a network of activists inside Syria, called the shelling of a number of villages in Aleppo Province "the most violent" since the army recently began a campaign to retake control of the area.

The rights group said rebels in the area had killed many government soldiers in recent months. It did not provide casualty figures.

World powers have failed to stop the violence in Syria, which activists say has killed more than 14,000 people since March 2011, when protesters first took to the streets to call for political reform.

In an interview with Le Monde published on Saturday, Kofi Annan, the special envoy to Syria for the United Nations and the Arab League, said more attention should be paid to Iran's role in efforts to find a political solution for Syria.

A cease-fire plan brokered by Mr. Annan went into effect on April 12, but both sides have repeatedly ignored it. "The evidence shows that we have not succeeded," Mr. Annan acknowledged. He said that Russia's role as an ally and arms supplier to Syria was crucial, but that Iran, too, "is a player" and "should be part of the solution."

Despite mounting international condemnation, Mr. Assad's government has largely held together. On Thursday, however, Brig. Gen. Manaf Tlass, an Assad confidant and the son of a former defense minister who helped ease Mr. Assad into power, defected to France.

General Tlass is the highest-ranking official to abandon the government so far, and Western powers and antigovernment activists expressed hope that his departure would encourage others to leave.

News of the defection largely overshadowed an international conference of the United States, its European and Arab partners and members of Syria's fractured opposition in Paris on Saturday.

Members of conference of the Friends of Syria group said they would provide means for opposition factions in Syria to better communicate among themselves and with the outside world and would increase humanitarian aid.