The death toll from devastating floods that struck eastern Libya has risen to 5,500, with another 7,000 injured, a local official said on Wednesday.

Osama Ali, the spokesman for the Tripoli-based emergency services, said that no final death toll could be determined yet because bodies are still being recovered from the affected areas.

Ali said that about 10,000 people have been reported missing and that 30,000 people have been displaced by the floods, adding the flood-hit regions face a severe shortage of basic supplies.

A tsunami-like river of floodwater swept through eastern Libya after Mediterranean storm Daniel made landfall on Sunday, causing extensive damage to infrastructure.

A 12-person UN Disaster Assessment and Coordination team has been deployed in Libya to support the world body's response to the massive flooding, the UN Office for the Coordination of Humanitarian Affairs (OCHA) said, noting that the United Nations is responding to calls for assistance and providing aid in the affected areas.

UN Secretary-General Antonio Guterres, at the beginning of a Wednesday press conference, again expressed his deepest condolences and full solidarity with all those affected by the flooding in Libya.

"The United Nations is mobilizing to support relief efforts and we will work in any and every way we can with partners to help get emergency assistance to those who so desperately need it."

UN humanitarians said search-and-rescue operations continue in Libya, led by national agencies, the military, the Libyan Red Crescent and local volunteers.

"The lack of accurate and reliable data across affected regions presents a significant challenge; access challenges and conflicting reports from multiple sources further add to the difficulties in coordinating and effectively deploying humanitarian assistance," OCHA reported earlier Wednesday in its Flash Update No.1 report.

The report said critical infrastructure, including healthcare, electricity, buildings, roads and telecommunications, were significantly damaged. However, there is progress in restoring electricity and communications to the affected areas.

"Many international partners indicated their interest to provide emergency response assistance," OCHA said. "The United Nations in Libya is preparing a flash appeal to garner and coordinate international support in response to Libyans' request for humanitarian assistance."

(With input from Xinhua)