The government of the Solomon Islands says the thousands of people in remote villages left homeless by a powerful earthquake and tsunami may not get help for another two days.

At least 28 people have been killed and up to 5,400 people are homeless and in urgent need of food, water and shelter. 

Strong aftershocks have continued since Sunday night's disaster and many residents are too scared to leave makeshift shelters in the hills. 

International aid is beginning to arrive, but officials say some islands are still out of contact and dozens of villages are unreachable by road.