AL-QASR, Lebanon -- Syrian soldiers backed by warplanes battled rebels for control of strategic hilltop villages near the Lebanese border on Friday, as government troops step up counterattacks against opposition forces threatening regime supply lines on the country's frontiers.
Bomb blasts and shots fired into the air to mourn a fallen Syrian government soldier could be heard on the Lebanese side of the border as fighting raged around Qusair, a contested central Syrian town near a key highway between Damascus and the coast.
The battles there came as government forces launched a second offensive against rebels in the province of Daraa on the Jordanian border, where the opposition has been making steady advances in recent weeks.
While President Bashar Assad's forces are stretched thin and much of the country has been allowed to slip into the hands of the rebels, the government is still fighting hard to keep control of airports, seaports, and roads linking them to the capital Damascus that are seen as essential to its survival.
Also on Friday, activists said rebels clashed with troops in the northeastern border city of Qamishli, two kilometres (miles) away from the border with Turkey. Fighting is rare in the predominantly Kurdish and Christian city, where rebels usually maintain a truce with the government.
It was not clear what prompted the clashes, which according to the Britain-based Syrian Observatory for Human Rights included members of the Islamic extremist Jabhat al-Nusra group.
Syria's rebels have gained momentum and made significant gains in the past weeks, largely due to an influx of arms. Arab officials and Western military experts say Mideast powers opposed to Assad have stepped up weapons supplies to Syrian rebels, with Jordan opening up as a new route.
While much of the recent fighting has focused in Daraa, rebels have also made advances in Homs province near Lebanon. The province saw some of the heaviest fighting during the first year of the Syrian conflict, which erupted in March 2011, and intermittent episodes of violence since.
On Friday, sporadic explosions inside Syria echoed across the Lebanese side of the border and an Associated Press reporter said Syrian warplanes carried out at least one airstrike inside Syrian territory near the town of Qusair.
Six people in the area, including two children, were killed when a shell struck their home, the Syrian Observatory for Human Rights said. Four rebel fighters were also killed.
The region overlooks a highway running between Damascus, Homs, and a coastal enclave that is the heartland of Syria's Alawites, the minority Shiite offshoot sect to which Assad belongs, and is also home to the country's two main seaports, Latakia and Tartus.
Overlooking Qusair from the Lebanese side are villages populated mostly by Shiite Muslim supporters of the Hezbollah militant group, which has backed Assad's regime. The rebels are overwhelmingly Sunni Muslim.
Syrian TV reported Friday that armed forces "restored peace and security" to Tal al-Nabi Mindo, a village that it described as occupying the highest hill in the region. Activists say it was taken a month ago by rebels.
Members of the Popular Committees, a Hezbollah-backed group that has fighters in the border villages, told the AP that the Syrian army captured Tal al-Nabi Mindo on Thursday after a day of heavy fighting. They said there were casualties on both sides. A commander who for security reasons identified himself only by his first name Mahmoud said the strategic hilltop village overlooks several towns and villages as well as the road that links Tartus to the central city of Homs and thereafter to Damascus.
Hezbollah has been accused by rebels of fighting alongside Assad's troops and launching attacks on rebels from inside Lebanese territory. But the border is porous and largely ignored by locals. The Popular Committee fighters, some of whom have lived in Syria for years, say they are defending their fellow Lebanese Shiites living in border villages there that were attacked by rebels.
In the Lebanese village of al-Qasr, which is on the opposite side of the border from Qusair, residents said they had gotten used to the shelling.
"Yesterday, the explosions were nonstop," said resident Ali Nasereddine, sitting in the garden of his two-story house, fewer than 100 metres (yards) from a Syrian army post.
A funeral was held for Riyad Kinyar, a Shiite Syrian soldier who was wounded in the fighting Thursday and died upon arrival in a hospital in al-Qasr. Later Friday, the soldier was taken across the border to his home town of Matraba for burial. Shooting in the air -- a sign of mourning -- could be heard from Syrian territory.
Analysts say a successful rebel attack on the regime's supply infrastructure could be a fatal blow to Assad.
"If the airports are destroyed and the ports that serve Damascus and Aleppo are lost to the regime, this would definitely speed up Assad's fall," said Joshua Landis, a Syria expert at the University of Oklahoma.
The Syrian conflict started with largely peaceful protests against Assad's regime in March 2011 but eventually turned into a civil war that has increasingly taken sectarian overtones. More than 70,000 people have been killed in the war, according to the United Nations.
Syrian warplanes carried out airstrikes elsewhere around the country on Friday, hitting multiple targets in Daraa, in the northern province of Raqqa whose province capital became the first to fall to rebel hands in March, and in the northern city of Aleppo, parts of which have been under rebel control since last summer.
In the northeastern city of Qamishli, rebels including the al-Qaida-affiliated Jabhat al-Nusra clashed with Syrian soldiers. Activists said the fighting appeared to break an undeclared truce that had spared the region the violence that has wracked other cities during the two-year-old civil war.
The government has informally handed over security to local Kurdish militias, who are mostly neutral in the civil war, on the understanding that rebels would not launch attacks there.
It was not clear what prompted the fighting at the entrance to Qamishli and near its airport. The Observatory said there were casualties on both sides.
