Children warm themselves around a fire in the besieged area of Homs on Jan. 27. (Reuters)

— The Syrian opposition on Monday said children as young as 2 remain missing in the country’s jails and state security buildings, disputing government claims that they hold no minors and casting doubt on the safety of civilians who take up an offer to flee the central city of Homs.

An exchange of prisoners has been a key issue as the two warring sides meet for peace talks in Switzerland for the first time during the three-year Syrian conflict. The Syrian opposition said it is in the process of compiling a list of about 50,000 citizens it believes to be detained, including 1,000 children, which it will submit to the United Nations this week after finalizing names. The government of President Bashar al-Assad has also accused the opposition of holding thousands of detainees.

The government denies that it holds children, and Information Minister Omran al-Zoubi claimed Monday that even child combatants recruited by rebel groups were not arrested. However, rights organizations said scores of child detainees, held in inhumane conditions in Syrian jails, remain a major concern.

With some detained during an evacuation in the Damascus suburbs last year, Homs residents say they fear that a similar fate may await individuals who take advantage of a government offer made Sunday to allow women and children safe passage out of besieged areas of the city.

Minors on the opposition list of those being held include the six children of Rania Abbasi, a dentist and former chess champion. The youngest on the list is her 2-year-old daughter. Abbasi and her children, who are all younger than 13, were allegedly detained during a raid on their Damascus home in March last year.

The big story

THE TALKS: On Friday, representatives of Syria's government and the opposition met for the first time as part of the Geneva II talks. Talks have continued between the two sides, which disagree on the fundamental issue of whether President Bashar al-Assad could have a place in a transitional government.

THE CONFLICT: More than 120,000 people have been killed and 2 million displaced in a conflict that began in March 2011 as largely peaceful protests against Assad. Fractious opposition groups are battling fighters loyal to Assad as well as those linked to al-Qaeda, part of the Islamic State of Iraq and Syria.

Timeline: Unrest in Syria

Almost three years after the first anti-government protests, conflict in Syria rages on. See the major events in the country's tumultuous uprising.

Her husband had been arrested at a checkpoint two days earlier, according to the opposition Center for Documentation of Violations in Syria, which said it did not know the motive for the arrests.

New York-based Human Rights Watch said it has received reports from former prisoners of infants being held in government detention centers with their mothers, as well as children as young as 10 being held on their own.

“We know that the Syrian government does not discriminate when it comes to holding not only children but women and the elderly as well,” said Lama Fakih, a Syria researcher for Human Rights Watch. “We know quite young children are being held in overcrowded cells without adequate access to food, water and medical treatment.”

Countries including the United States have urged Syrian authorities to let aid convoys into war-ravaged Homs — where residents say they have been under siege for 20 months — rather than insisting that women and children leave.

Residents of the Damascus suburb of Moadamiya say minors were detained during evacuations there in October that were brokered after reports of children starving to death.

Ahmed Mahmoud, 28, said his 16-year-old cousin was among them. “He took the bus out, but I was told he was ordered off and taken to the military air base,” he said. “We haven’t heard from him since.”

Syrian Opposition Coalition spokesman Oubai Shahbandar described the detention of children by Syrian authorities as “systematic.”

“The women and children are dying to leave this area,” said Ahmed Abu Loui, a media activist in the Old City of Homs. “But we cannot trust the regime promises; they will betray any promises they make.”

Rights groups have also criticized more-mainstream rebel groups for violations against minors, including the use of child soldiers. Meanwhile al-Qaeda-linked groups are believed to hold dozens of journalists and aid workers and to have executed at least one child.

Speaking to Syrian state television in Geneva, Zoubi said that the Syrian authorities do not arrest children. If those involved in armed groups are apprehended, their age and the “moral and psychological influences they were subjected to” are taken into account, he said.

Ahmed Ramadan contributed to this report.