Syrian state TV has broadcast video of government troops inside the historic city of Palmyra, which has been under the control of the Islamic State of Iraq and the Levant (ISIL) group since May last year.

The footage published on Thursday shows Syrian army vehicles and soldiers moving around areas of the city with some of its famed ruins clearly visible.

The advances - if verified - come amid a government offensive to capture the city that began earlier this month with support from Russian fighter jets.

The UK-based Syrian Observatory for Human Rights said fighting was still ongoing outside the city on Thursday, after a rapid advance the day before brought the army and its allies right up to its outskirts.

ISIL (also known as ISIS) captured the city, also known as Tadmur, in May last year and began a campaign of destroying some ancient sites and using others to stage mass executions.

Syria is in the midst of cessation of hostilities between government forces and opposition rebel factions, which has significantly reduced violence in the country.

The agreement excludes al-Nusra Front and ISIL, which are considered "terrorist" groups by the Syrian government.

The uprising that turned into a civil war in Syria began five years ago. More than 270,000 people have since been killed and millions of people have fled to neighbouring countries and Europe.

ISIL began capturing large swaths of territory in Syria in 2013 after wrestling territory off rebel groups and later through its own offensives against both the opposition and government.

The group has held on to most its gains but has lost areas in northern Syria to Kurdish groups backed by US air strikes and Syrian forces backed by Russia.

Al Jazeera