A Syrian rights group says security forces have attacked a rebellious town in the country's central province of Hama, killing 16 people including children.

The Britain-based Syrian Observatory for Human Rights says government artillery and gunfire hit the town of Souran on Sunday. There was no independent confirmation of the casualties.

Elsewhere, a roadside bomb exploded near a team of U.N. officials and journalists who were touring the Douma suburb of Damascus. No one was hurt by the blast, which happened about 150 meters away from the group that included visiting U.N. peacekeeping chief Herve Ladsous and the head of U.N. observers in Syria, Maj. Gen. Robert Mood.

A Syrian security official said gunmen had been active in Douma prior to the explosion, attacking and wounding about 30 security personnel. Recent fighting between government and rebel forces in the district has left its streets largely deserted. Douma has been been a major center of the 14-month uprising against Syrian President Bashar al-Assad's 11-year rule.

Two senior aides of Mr. Assad appeared on state television on Sunday to angrily denounce claims that rebels had assassinated them. Rebels had posted the claims on the Internet, saying they had killed several senior officials including Interior Minister Mohammad al-Shaar and former defense minister Hassan Turkmani in a sophisticated attack.

A deadly shooting also was reported in Lebanon, where the conflict in neighboring Syria has triggered deadly sectarian violence in recent days. Lebanese troops opened fire on a car carrying a Sunni cleric and his aide as it sped through a military checkpoint in the country's north, killing the two men. Cleric Ahmed Abdul-Wahid and his aide were members of Lebanon's anti-Assad alliance that supports the Syrian revolt.

The Lebanese military issued a statement expressing “deep regret” for the killings and saying an investigation has been launched. The cleric's supporters protested the shooting by burning tires and blocking roads in parts of northern Lebanon.

Fighting between pro- and anti-Assad groups in the northern Lebanese city of Tripoli killed at least eight people in the past week. The fighting involved Lebanese Alawites who belong to the Syrian president's minority Muslim sect and Lebanese Sunnis who sympathize with the largely-Sunni led uprising against Mr. Assad.