Approximately 50,000 civilians, including 20,000 children, remain trapped with limited access to food and water as the Iraqi troops battle the Islamic State group fighters in Fallujah, Iraq. 

According to news.com.au, the United Nation's Children's Fund (UNICEF) on Wednesday issued a warning to the Iraqi troops and ISIS militants to "protect children inside Fallujah." 

The UN said there were reports that ISIS militants were using families as human shields. 

The UNICEF's representative in Iraq, Peter Hawkins, was quoted by news.com.au as saying: "UNICEF calls on all parties to protect children inside Fallujah, provide safe passage to those wishing to leave the city and grant safe and secure environments to displaced civilians... Children face the risk of forced recruitment into the fighting, strict procedures for security screening and separation from their families... Children who are recruited see their lives and futures jeopardised as they are forced to carry and use arms, fighting in an adult war."

Reports suggest that food and medicine are running out and there is limited supply of safe drinking water. A staff member of Fallujah's main hospital was quoted by news.com.au as saying that it received reports of 32 civilians killed on Monday.

The UN apparently said an estimated 3,700 civilians have managed to escape Fallujah and reach displacement camps in the past week. The largest fleeing included exhausted and hungry women and children on Saturday night.

Haider al-Abadi, prime minister of Iraq, reportedly lauded the "remarkable advance" by the Iraqi troops and emphasised that protecting civilian lives and minimising Iraqi casualties was the government's top priority. He vowed to "hoist the Iraqi flag inside Fallujah in the coming few days."