Commissioner Kristalina Georgieva has called for international humanitarian law to be respected, and civilians caught up in the conflict in Sirte to be allowed to leave the Libyan city safely.
The situation in the besieged city is dire, experts from the European Commission's Humanitarian Aid and Civil Protection Directorate General in Libya have confirmed.
Commissioner Georgieva said: "Our experts are warning that civilians are in grave danger as a consequence of the fight for control of Sirte.
"Despite a steady movement of population out of the city, we believe that thousands remain and are being prevented from leaving. I strongly appeal not to use civilians as human shields, but to let them leave the city in safety. Once again, I urge that international humanitarian law is respected."
The humanitarian community has pre-positioned medical and essential supplies near the conflict in order to provide assistance once access is possible. Funding of €3 million has been reserved by the Commission to respond to the needs triggered by the ongoing fighting.
The European Union is the largest provider of humanitarian assistance in the Libyan crisis, with a contribution of more than €154 million so far. More than €80.5 million of total EU assistance is from the European Commission.