The Syrian army appears to have ended a rebel siege of Aleppo central prison that has lasted more than a year. The victory is only the latest for government troops, who are pushing to rid the city entirely of rebels.

News that the Aleppo central prison siege had been successfully put down by government troops on Thursday appears to have been confirmed, ending a stand-off that began in April 2013.

The prison, which holds an estimated 3,000 inmates, had been a stronghold for government forces that was surrounded and isolated by rebel fighters.

The British-based Syrian Observatory for Human Rights, which relies on its network of activists across Syria, said government forces had entered the prison at dawn.

This assertion was backed up by both Lebanon's Al-Mayadeen and Al-Manar television channels, which have reporters based in the country. Government forces had begun to end the siege on Tuesday, backed by the Syrian air force.

Activists from the Observatory said they had been told that there was a sound of heavy army vehicles inside the compound on Wednesday - and the sound of celebratory gunfire.

Aim to take city before election

If forces loyal to President Bashar al-Assad can maintain clear access to the prison, the government would effectively have gained control of the northeastern approach to Aleppo. The prison is the government's only major holdout between Aleppo and the Turkish border.

Aleppo has become fragmented into government and rebel-controlled areas since opposition fighters launched a major offensive in the north in mid-2012. The government appears keen to retake opposition areas of Syria's major cities ahead of presidential elections in June.

The Syrian army has made several important gains in recent weeks, having also retaken the city of Homs. Rebels were evacuated from the central city, which was a focal point for the uprising against Assad, as part of an exchange for government troops held prisoner by the opposition.