BEIRUT — The Syrian government has released 13 jailed women, an official and an activist group said on Wednesday — a move that may be part of an ambitious regional prisoner exchange.

BEIRUT — The Syrian government has released 13 jailed women, an official and an activist group said on Wednesday — a move that may be part of an ambitious regional prisoner exchange.

Meanwhile, al-Qaida-linked rebels strengthened their hold on an ancient Christian town north of Damascus, activists said.

In The Hague, the organization tasked with destroying Syria’s chemical weapons program and its arsenal said they had visited more than three-quarters of the sites declared by the government. The group said it expected to meet a Nov. 1 deadline to make declared chemical weapons production facilities inoperable.

The Britain-based Syrian Observatory for Human Rights said the women were released Tuesday morning from the headquarters of the Damascus provincial government, but said they hadn’t been able to contact them.

The Observatory relies on a network of activists on the ground for its information.

The women may have been freed as part of a three-way exchange that began on Oct. 18. It saw Syrian rebels release nine Lebanese men held for a year and a half. Lebanese gunmen simultaneously released two Turkish pilots held since August.

Lebanese officials had said a number of imprisoned Syrian women were meant to be let go to meet the demands of the Syrian rebels. They were not immediately available for comment Wednesday.

It’s unclear how many women are held by Syria’s government, nor how usual it is for 13 to be released simultaneously. A Syrian government official confirmed the women were freed, but would not provide further details. He spoke anonymously, because he wasn’t authorized to talk to media.

The deal underscored how far Syria’s civil war, now in its third year, has spilled across the greater Middle East. It appeared to represent one of the more ambitious negotiated settlements to come out of the war, in which the rival factions remain largely opposed to any bartered peace.

Fighting continued in the Christian town of Sadad and desperate residents tried to flee, as hard-line Muslim rebels clashed with soldiers and gunmen loyal to the government of President Bashar Assad.

The Observatory said fighters from the two al-Qaida-linked groups, the Jabhat al-Nusra or Nusra Front and the Islamic State in Iraq and the Levant, took a checkpoint that gave them control of the western part of the town. They also took control of the road leading to Damascus. Residents were fleeing in the opposite direction, to the central city of Homs some 56 kilometers (35 miles) away.

Residents told the group that five people were killed by snipers. The residents believed the snipers were rebels.

Clashes have been ongoing in Sadad for the past three days. The fighters seem to have appears to have targeted Sadad because of its strategic location near the main highway north of Damascus, rather than because it is Christian. But hard-liners among the rebels are hostile to Syria’s Christian minority, which fears the radicals and tends to favor Assad. Other al-Qaida-linked fighters have damaged and desecrated churches in areas they have seized.

Also Wednesday, a spokesman for international inspectors said they had visited 18 out of 23 chemical weapons sites declared by Syria, racing to meet tight deadlines set by the U.N. to destroy the country’s chemical weapons arsenal and their ability to produce the weapons.

Three teams of inspectors had carried out "functional destruction activities" at almost all the sites, said spokesman Michael Luhan of the Organization for the Prohibition of Chemical Weapons. He briefed reporters at the OPCW’s headquarters in The Hague.

Initial site visits and preliminary destruction activities are expected to be completed by Nov. 1. Luhan said they expected that by that date, they will have rendered "inoperable" Syria’s declared chemical weapons production facilities and machinery for mixing chemicals and filling munitions.

The three teams of inspectors had "good access" to sites so far, and the Syrian government was cooperating, said Luhan.

He wouldn’t comment on how inspectors were to reach sites under rebel control.

The U.N. Security Council has tasked the OPCW with a tight deadline to Syria’s chemical capabilities, a matter complicated by the country’s three-year raging civil war.

By Oct. 27, Syria must submit a plan for the destruction of its stockpile. By Nov. 1, the inspectors must complete verification of the inventory and render production, mixing and filling facilities unusable. By Nov. 15, they must adopt a plan for destroying the stockpile, aiming for completion by mid-2014.

Luhan said that as the first phase of the operation was winding down by the end of October, the number of inspectors would be temporarily down to 15 next week.

They currently have 27 inspectors in Syria and one more in Lebanon assisting logistics.

The toll of the Syrian war has been crushing. Over 100,000 people have been killed, and almost a third of the population has fled its homes to escape violence or the resulting economic hardships.

Even fleeing is no guarantee of safety. The Observatory reported Wednesday that a Syrian woman trying to escape to neighboring Jordan was raped and killed, along with her daughters aged one and three, allegedly by the man who was supposed to take her across the border. The Observatory said the incident occurred in the Zizon valley on the Jordanian-Syria border on Monday.

The man also stole all her cash: $87. Syrian residents found the bodies days later. The Observatory said Syrian rebels captured and killed a suspect who they said confessed to the crime.