BEIRUT (AP) — Syrian rebels stepped up their siege of a military base in north of the country Friday as government warplanes bombed surrounding areas to support the defenders, activists said.

The fighting around Mannagh airbase near the Turkish border came as foreign ministry officials in Ankara said two Syrian air force generals had defected and crossed the border.

Rebels have been advancing in different areas in northern Syria, capturing several bases in and around the embattled city of Aleppo in recent weeks.

“The fighting did not stop all night around Mannagh airport,” said Aleppo-based activist Mohammed Saeed. He added that Syrian military warplanes bombed rebel positions around the camp in an attempt to take the pressure off the base.

The Britain-based Syrian Observatory for Human Rights said rebels reached the edge of the air base late Thursday and that heavy fighting continued into Friday.

The Observatory and Saeed also reported heavy clashes between troops and rebels in an around the Palestinian refugee camp of Handarat in Aleppo, Syria’s largest city and commercial center, which opposition fighters have been trying for six months to capture.

In Turkey, foreign ministry officials said Friday that the two defecting generals were “regional Syrian Air Force commanders” and are now in a camp where army defectors stay in the country.

They refused to give the generals’ identities or say how they escaped from Syria. They spoke anonymously as they were not authorized to talk to the press.

The defection comes days after the commander of Syria’s military police Maj. Gen. Abdul-Aziz Jassem al-Shallal defected to Turkey. Al-Shallal is among the most senior members of Assad’s military to defect.

Dozens of Syrian generals have defected since the country’s crisis began in March 2011.

In other parts of the country, the Observatory reported fighting and shelling in areas including some neighborhoods of the capital Damascus, its suburbs, the central province of Hama and Homs and the region of Quneitra on the edge of the Israeli-occupied Golan Heights.

The Observatory reported heavy clashes in the southern province of Daraa, mostly in the town of Busra al-Harir, and the Tel Shehab area near the border with Jordan.

Meanwhile, a government airstrike on a town in north Syria on Friday killed 14 people, mostly women and children, anti-regime activists said.

The Observatory said the 14 were killed in a strike on the town of al-Safira, south of the northern city of Aleppo. The dead included two women and eight children.

An Aleppo activist who spoke on condition of anonymity for security reasons provided a list of the names of the dead and said the government often strikes the town because rebels are attacking a large military complex on its outskirts.

Rebels clashed with soldiers there on Friday, he said.

A video posted online that purported to show the site of the strike showed a large area covered with the rubble and the walls sheared off of a row of buildings nearby.

The video appeared genuine and corresponded to other AP reporting.

Syrian rebels are fighting a 21-month-old revolt against Assad’s regime. Activists say more than 40,000 people have been killed in the crisis, which began with pro-democracy protests but has morphed into a civil war.

Copyright 2012 The Associated Press.