Syrian troops backed by tanks and warplanes are fighting to repel an attack on the central prison in Aleppo after rebels blew up its walls in suicide car bombings, according to a watchdog.
The fighting comes as the UN General Assembly prepares to vote on a resolution condemning the government of President Bashar al-Assad.
"Fierce fighting is taking place within the walls of the compound" of the prison in the northern city, said the Syrian Observatory for Human Rights, an opposition group based in the UK, voicing concern over the fate of the inmates.
Around 4,000 prisoners, including ideological opponents and common-law criminals, are held in the prison on the outskirts of the city, which is largely under rebel control, Rami Abdel Rahman, the head of the Observatory, said.
Regime forces fired tank shells and launched air raids around the jail to repel the rebel attack, igniting fires and damaging neighbouring houses, the Observatory said.
A child was killed and seven members of a family were wounded in the bombings, it added, citing activists on the ground.
In the capital, an explosion reportedly rocked Ummayad Square in central Damascus. A soldier at the scene reported injuries in the blast caused by a sticky bomb attached to a car near a checkpoint outside the army chief of staff offices.
In-depth coverage of escalating violence across Syria
The Observatory, which relies on a network of activists and medics across the country, also reported clashes in the central province of Hama and on the international highway in Damascus province.
Elsewhere, violent clashes were reported in Idlib province, in the northwest, and Daraa, in the south.
The official news agency SANA, meanwhile, said that internet and telephone lines were down because of a faulty fibre optic cable, in the second such incident in the past week.
Syria's internet was down for two days last week, with state media blaming the blackout on a technical fault but activists and a watchdog accusing the regime of deliberating cutting the connection to shield military operations.
In violence across the country on Tuesday, 99 people were killed, said the Observatory, which has compiled a total of more than 94,000 deaths in the two-year conflict between the regime and its opponents.