A C-17 military plane from Al Udeid Air Base in Qatar the delivered 11 pallets of aid, with two more shipments of food and water coming in the next 24 hours, US Central Command said in a statement.

"The US is actively engaged in delivering food, water, and medical supplies to the Lebanese Armed Forces to meet the critical needs of the Lebanese people," General Frank McKenzie was quoted as saying.

Many Lebanese are angry at the country's leadership that is widely viewed as corrupt and incompetent, and some fear international aid may be diverted from those needing it most.

"We're well aware of some of the concerns with whom the aid would go to and ensuring that the aid gets to the people of Lebanon that need it most," Pentagon spokesman Jonathan Hoffman said.

Further assistance will be coordinated with the Lebanese army, the US embassy in Lebanon and the US international aid agency, USAID, Centcom said.

Public anger in Lebanon is on the boil over the blast caused by a massive pile of ammonium nitrate that had for years lain in a ramshackle portside warehouse.

It left at least 149 dead and 5,000 injured, and hundreds of thousands of people homeless. Rescuers and families are still searching for dozens more missing since the blast.

The death toll was expected to rise as rescue workers keep digging through the rubble. The blast zone is now a wasteland of blackened ruins, while whole neighborhoods were largely destroyed.

The fallout is expected to cost billions in a small country already plunged into an unprecedented economic and social crisis, battling the coronavirus, and where almost half of the inhabitants live in poverty.