BEIRUT - Syria's conflict spilled further into Lebanon on Saturday when mortar fire from President Bashar al-Assad's forces hit villages in the north, killing five people after rebels crossed the border to seek refuge, residents said. Rebels fighting to unseat Assad have used north Lebanon as a base and his forces have at times bombed villages and even pursued insurgents over the border, threatening to stoke tension in Lebanon, whose sectarian divisions mirror those in Syria. Residents of Lebanon's Wadi Khaled region said several mortar bombs hit farm buildings five to 20 km (3 to 12 miles) from the border at around 2 a.m. At midday villagers reported more explosions and said they heard gunfire close to the border. In the village of al-Mahatta, a house was destroyed, killing a 16-year-old girl and wounding a two-year old and a four-year old, family members told Reuters. A 25-year-old woman and a man were killed in nearby villages, residents said. Two Bedouins were killed in the village of Hishe, which straddles a river demarcating the border, when two rocket-propelled grenades fired from within Syria hit their tent, according to local residents. Lebanon's army confirmed one of the deaths and said several Syrian shells had landed in Lebanese territory, but had no further information. Lebanese President Michel Suleiman issued a statement regretting the deaths and promising an investigation. Syria's bloodshed has also encroached on the territory of Turkey, a much bigger and more militarily powerful neighbour. Ankara, a former Assad friend turned foe, reinforced its frontier and scrambled fighter aircraft several times after Syria shot down a Turkish reconnaissance jet on June 22. The diplomatic stalemate that has frustrated international efforts to bring about a peaceful transition in Syria persisted on Saturday as China joined Russia in rejecting a U.S. accusation that Beijing and Moscow were obstacles to a solution. In Syria, the army bombarded towns across northern Aleppo province on Saturday in a concerted effort to root out insurgents who have taken control of some areas, the anti-government Syrian Observatory for Human Rights said. "The bombing is the heaviest since the start of military operations in rural Aleppo in an attempt to control the region after regular Syrian army forces suffered heavy losses over the past few months," the British-based activist group reported. It said three people had died, including two rebels. The official Syrian news agency SANA said troops foiled infiltration attempts by armed men from Turkey and Lebanon on Friday. It said one clash "resulted in the killing, injury of dozens of the infiltrated gunmen". In Idlib province, SANA said, an armed terrorist group was prevented from infiltrating from Turkey in Harem region. It quoted a source as saying a number were killed "while the rest managed to flee back into the Turkish territories". The Observatory said many families had been displaced and water, electricity and medical supplies were running short. Aleppo, Syria's second largest city and commercial hub, has been largely spared of the violence. But the outskirts of the city and the wider province have seen rebels gaining territory since the uprising began 16 months ago. SANA reported a clash "with an armed terrorist group in Azaz area north of Aleppo as it was attacking the citizens and perpetrating killings". It said eight gunmen were killed and six cars equipped with machineguns plus a stolen ambulance were destroyed. The agency named the dead.