Syrian troops have ended the siege of the main prison in the northern city of Aleppo, ending a months-long attempt by rebels to free the inmates inside, opposition activists and a state media have said.
The sprawling Aleppo Central Prison, which holds an estimated 4,000 inmates, has witnessed deadly clashes between government and opposition forces for the past year.
Rebels had repeatedly barrelled suicide car bombs into the front gates and fought guards and troops holed up inside.
Government troops bombarded rebel positions around the prison after taking over a strategic hill nearby on Wednesday morning, Syrian state television reported.
"This is a major blow for rebels," Al Jazeera's Rula Amin, reporting from Beirut in neighbouring Lebanon, said. "They besieged the prison for 13 months, trying to free prisoners.
"But the siege has caused a humanitarian crisis in the prison. Regime troops had to airlift some supplies to the guards and the prisoners."
The Syrian Observatory for Human Rights, an activist monitoring group, said there were fears that government forces might kill some of the inmates and "claim that they died during the rebels' siege of the prison".
Aleppo has been carved into rebel- and government-controlled areas since opposition fighters launched an offensive in the north in mid-2012.
The Syrian army appears intent on taking opposition-held parts of the country's major cities before the country's June presidential election.
The prison lies on a highway about six kilometres north of the city of Aleppo, once Syria's commercial capital.
The civil war devastated the city, leaving rebels controlling the east and the forces of Bashar al-Assad, the president, holding the west.
"The air raids were astonishing," said Ibrahim Saeed, an activist based in Aleppo province. "The air force tipped the balance of power. More than 100 barrels bombs struck the area around the prison."
Saeed said the next target of government forces appears to be the nearby town of Handarat, then the Kindi Hospital, in an attempt to close rebel supply lines from the countryside into Aleppo.
He added that after the capture of the prison, Assad's forces are now close to a command centre of the Islamic Front alliance, a coalition of seven rebel groups fighting the government.
The centre is in an army infantry base that was captured by rebels two years ago.
Activists say more than 160,000 people have been killed since the conflict started in March 2011 which saw largely peaceful protests against Assad's rule deteriorate into civil war.