Updated

The International Committee of the Red Cross is urging those fighting in Syria's Aleppo to do all they can to protect and spare civilian lives.

The ICRC says in a statement on Tuesday that thousands of people with no part in the violence "have literally nowhere safe to run."

The dramatic appeal came after Syrian military announced the previous day it gained control of 99 percent of the former opposition enclave in eastern Aleppo, signaling an impending end to the rebels' four-year hold over parts of the city.

ICRC says a deepening humanitarian catastrophe and further loss of life can be averted only if the basic rules of warfare — and of humanity — are applied.

Retaking Aleppo would be President Bashar Assad's biggest victory yet in the civil war.