Human Rights Watch on Friday urged Syrian regime forces to immediately let desperately needed aid into besieged districts of Aleppo and to allow civilians to leave the city.

The New York-based group appealed to forces loyal to President Bashar al-Assad to abide by international humanitarian law.

More than 200,000 people living in opposition-controlled parts of the battered northern city have been effectively living under siege for more than two weeks.

Residents have reported food and fuel shortages and skyrocketing prices.

"Syrian government forces are repeating the terrible siege tactics in densely populated eastern Aleppo that devastated civilian populations in other towns in Syria," HRW's deputy Middle East director Nadim Houry said.

"Syrian authorities should allow aid in and permit civilians wishing to leave to do so safely." 

The United Nations says that nearly 600,000 Syrians already live under siege countrywide, most surrounded by government forces though rebels and jihadist groups also employ the brutal tactic. 

"We haven't seen vegetables in weeks and the air strikes are not giving us a break," Feras Badawi, a journalist in eastern Aleppo city, told HRW.

On Thursday, at least 15 civilians including six children were killed in government bombardment of two rebel-held districts in the city, according to the Syrian Observatory for Human Rights. 

"It is a crisis situation in our city... The lines of people at shops to stock up on rations are extremely long. We are really expecting a famine in a few days," said Ibrahim Abu al-Laith, a rescue worker in east Aleppo.

Aleppo has been rocked by violence since mid-2012, just over a year after Syria's conflict first broke out with anti-government protests. 

The city has since been roughly divided between government forces in the west and rebel control in the east.

An enormous explosion detonated by rebels in an underground tunnel on Thursday left at least 38 regime soldiers and allied forces dead in Aleppo's Old City, the Observatory said.

Repeated attempts by regime ally Russia and the United States to secure a freeze in fighting in the city have failed.

HRW called on both world powers to use their "influence to press the Syrian government and other warring parties to allow unhindered access to aid, particularly to all hard-to-reach and besieged areas of the country." 

Source: AFP