Solomon Islanders began voting Wednesday in an election that could reshape regional security, with citizens effectively choosing if their Pacific nation will deepen ties with China.

Prime Minister Manasseh Sogavare has pledged to further bolster relations with Beijing if he is re-elected, while his main challengers want to wind back China's growing influence.

Swelling crowds gathered early outside guarded election booths in the capital Honiara, pouring in to cast their ballots when voting opened at 7:00 am local time.

Voting day is an immense logistical challenge in Solomon Islands, a nation of some 720,000 people spread across hundreds of volcanic islands and coral atolls.

Ballot boxes and voting papers have been despatched by boat, plane and helicopter to the many far-flung villages that make up the "Hapi Isles".

Teams of international observers are on hand to watch over voting in a nation where elections frequently spell trouble. 

Police from Australia, New Zealand and Papua New Guinea are on the ground to help the stretched local forces keep the peace. 

Preparing for the prospect of violence after the vote, the Chinese embassy in downtown Honiara hastily erected a temporary steel fence out front this week. 

It is the first election since Solomon Islands severed diplomatic ties with Taiwan in 2019, giving its backing to Beijing's "One China" principle instead.

Security fears

Solomon Islands has veered into China's orbit under the mercurial Sogavare, who signed a security pact with Beijing in 2022. 

Although the final details are murky, Australia and the United States fear the pact is the first step towards a permanent Chinese military base in the South Pacific.

Sogavare's main rivals include Peter Kenilorea, a former United Nations lawyer who wants to abolish the China pact. 

Human rights campaigner Matthew Wale and economist Gordon Darcy Lilo — a former prime minister — are among other prominent opposition figures.

Government critic and opposition figurehead Daniel Suidani, a former provincial premier, labelled China's actions "alarming" in the lead-up to election day. 

"During these past five years, there have been so many things that China was involved in. It's really alarming at the moment," he told AFP.

Chinatown torched

Sogavare's embrace of Beijing in 2019 partly fuelled a wave of anti-government riots that tore through the Chinatown district in the capital Honiara.

Violence returned in 2021, when angry mobs tried to storm parliament, torched Chinatown and attempted to raze Sogavare's home.

Solomon Islands' elections are peculiar in that voters do not choose their prime minister.

Instead, they elect representatives who negotiate behind closed doors to form a ruling coalition and pick a leader.

The coalition process can sometimes run on for weeks before the nation is finally presented with a government and a prime minister.

Elections are always boisterous, often tumultuous and sometimes violent in Solomon Islands. 

In 2000, then-prime minister Bart Ulufa'alu was forced to resign after he was kidnapped by gunmen. 

International peacekeepers were deployed to quell post-election violence in 2006, with premier Snyder Rini pushed out of office after eight days.

Honiara residents have frequently cited creeping poverty and the lack of jobs as their main issues in the lead-up to polling day.