BEIRUT (AP) -- Syrian activists said rebels shot down a government warplane over the northern province of Idlib on Thursday, the second time in a week that opposition fighters claimed to have brought down an aircraft in the escalating civil war.
Two activist groups, The Local Coordination Committees and the Britain-based Syrian Observatory for Human Rights, said the plane was seen crashing near the Abu Zuhour air base. Idlib-based activist Alaa al-Din said rebels shot it down with heavy machine guns.
A video broadcast on the pan-Arab satellite station Al-Arabiya shows what appears to be a person parachuting and rebels cheering and claiming he was the pilot. The video's authenticity could not be verified.
The government had no immediate comment, and the report couldn't be independently confirmed. But a brief video clip posted by an Idlib-based rebel group showed the body of a man in an olive-green pilot overall with an apparent head wound. A short distance away lay what appeared to be a white parachute.
The authenticity of the video, dated Aug. 30, could not be independently verified.
Over the past month, President Bashar Assad's regime has been relying much more heavily on air power, escalating the fight with rebels as its ground forces have been stretched thin fighting on many fronts including Syria's two largest cities -- Damascus and Aleppo. The military has conducted air raids on the northern regions of Idlib and Aleppo near Turkey as well as the eastern province of Deir el-Zour.
The increased use of air power is likely a factor in the high daily death tolls, which activists say have been averaging 100-250 lately.
Later in the day, Human Rights Watch said government forces have killed scores of civilians over the past three weeks by bombarding at least 10 areas where they were lining up at bakeries near and around Aleppo.
"Day after day, Aleppo residents line up to get bread for their families, and instead get shrapnel piercing their bodies from government bombs," researcher Ole Solvang said in a statement after returning from the northern city.
The rebels' claim of shooting down the warplane on Thursday was the third time this month they said they have brought down a government aircraft.
Earlier this week, the opposition fighters said they shot down a helicopter in the Damascus neighborhood of Jobar while the government confirmed a chopper crashed in nearby area of al-Qaboun. On Aug. 13, rebels claimed to have shot down a regime MiG-23 warplane and captured the pilot in Deir el-Zour. Syria says the pilot ejected after a technical malfunction in the fighter jet.
If the rebel claims are confirmed, it would be another blow to Assad's regime, which has been struggling to put down rebel challenges around the country even though its firepower is far superior to the opposition's.
Rebels appear to be targeting air bases with increasing frequency.
Earlier in the day, the Observatory reported explosions inside the Abu Zuhour air base in Idlib, near where the plane was reported to have been shot down. It added that rebels have captured parts of the compound.
On Wednesday, state news agency SANA reported that government forces repulsed a major rebel attack on a helicopter military base of Taftanaz, also in Idlib province.
Idlib, which borders Turkey, has been one of the major rebel strongholds since last year. Although government troops control the provincial capital, which carries the same name as the province, rebels move freely in towns and villages in the district.
In Iran, Egyptian President Mohammed Morsi described the Syrian regime as "oppressive" and called for it to transfer power to a democratic system. He was speaking at the opening of a summit of the 120-member Nonaligned Movement in Tehran.
Morsi's comments angered the Syrian delegation, which walked out in protest, according to Syria's state-run media.
Syrian Foreign Minister Walid al-Moallem, who is also in Tehran, was quoted by the state-owned Al-Ikhbariya TV as saying: "Morsi's comments violated the traditions of the summit and are considered interference in Syrian internal affairs." He also accused Morsi of "instigating blood shedding in Syria."
Iran is Syria's closest ally in the Middle East.
Morsi is an Islamist from the Muslim Brotherhood, the most powerful political force to emerge from last year's uprising that ousted longtime authoritarian leader Hosni Mubarak. The Sunni fundamentalist group opposes Shiite Iran's staunch backing of the Syrian regime and its lethal crackdown on the largely Sunni opposition. Assad belongs to the minority Alawite sect, an offshoot of Shiite Islam.
Assad, speaking in a rare TV interview broadcast on Wednesday, said his armed forces will need time to defeat the rebels -- an acknowledgement of the difficulties the military is facing in winning the civil war.
A member of Syria's main opposition group said his comments aimed to explain his security forces' failure in putting down the rebellion. British-based opposition activist Ausama Monajed, who is a member of the Syrian National Council, said in a telephone interview that Assad's statements tried to "justify the failure of the security solution."
"He is trying to boost the morale of his supporters. He is trying to justify the failure of the military solution that has been going on for months," Monajed said. "His comments were addressed to his constituency."
Activists estimate more than 20,000 people have been killed since the uprising against Assad's began more than 17 months ago.