A woman votes at a polling station in Honiara, Solomon Islands. [AFP]

Vote counting was under way Thursday in the South Pacific's Solomon Islands, a contest keenly watched from afar as China's efforts to stamp its mark on the region are tested.

Ballots were trucked into a heavily guarded counting centre in the capital Honiara, watched over by international teams of uniformed Fijian soldiers and Australian police.

In the outermost reaches of the volcanic archipelago, ballot boxes were still making their way to provincial hubs for tallying - potentially delaying some results by days.

Chief electoral officer Jasper Anisi said that "everything is peaceful" so far - no mean feat in a nation where elections have often spilled over into violence.

Hand counting the paper votes is only the start of an arduous electoral process.

Once the parliament's 50 members are finally elected, they will begin bartering with each other behind closed doors to cobble together a ruling coalition.

Only once the dust has settled from this will a prime minister emerge.

Incumbent prime minister Manasseh Sogavare is among China's most prominent champions in the region, while his main challengers view Beijing's growing influence with a mix of scepticism and alarm.

Startling and unproven claims of foreign interference have upped the ante for a vote already billed as one of the nation's most crucial in a generation.

State-backed Chinese news outlets have pushed reports that the United States might orchestrate riots to block Sogavare from returning to power.

US Ambassador Ann Marie Yastischock said such rumours were "blatantly misleading".

"We strongly refute allegations being made in known propaganda outlets that claim USAID and the US Government has sought to influence the upcoming election in Solomon Islands," she said in a statement.