Eyewitnesses and local media reported crowds had defied a government lockdown to take to the streets.
Live images showed several buildings engulfed in flames and plumes of thick black smoke billowing high above the capital.
It followed widespread disorder in Honiara on Wednesday, when demonstrators attempted to storm parliament and depose Prime Minister Manasseh Sogavare.
Businesses operated by Honiara’s Chinese community were looted and burned, prompting Beijing’s embassy to express “serious concerns” to the Solomons‘ government.
“(The embassy) made representations requesting the Solomon Islands to take all necessary measures to strengthen the protection of Chinese enterprises and personnel,” it said in a statement.
Sogavare said his government was still in control.
“Today I stand before you to inform you all that our country is safe — your government is in place and continues to lead our nation,” Sogavare said, adding that those responsible “will face the full brunt of the law”.
After failing to break into parliament on Wednesday, the rioters regrouped a day later, running amok in the Chinatown area and ransacking a police station, a local resident told AFP.
The man, who did not want to be named, said police had erected roadblocks but the unrest showed no sign of abating.
“There’s mobs moving around, it’s very tense,” the resident said, as local media reported looting and police using tear gas.
Most of the protesters in Honiara are reportedly from the neighbouring island of Malaita, where people have long complained of neglect by central government.
The island’s local government also strongly opposed the Solomons’ decision to switch diplomatic allegiance from Taiwan to China in 2019, in a move engineered by Sogavare who critics say is too close to Beijing.
Opposition leader Matthew Wale called on the prime minister to resign, saying frustration at controversial decisions made during his tenure had led to the violence.
“Regrettably, frustrations and pent-up anger of the people against the prime minister are spilling uncontrollably over onto the streets, where opportunists have taken advantage of the already serious and deteriorating situation,” Wale said in a statement.
Similar inter-island rivalries led to the deployment of an Australian-led peacekeeping force in the Solomons from 2003 to 2017 and the unfolding situation will be closely monitored in Canberra and Wellington.
New Zealand’s foreign ministry said Thursday it had not been approached by the Solomons’ government for assistance. Australian officials did not immediately respond to requests for comment.
There was rioting following general elections in 2006, with much of Honiara’s Chinatown razed amid rumours that businesses with links to Beijing had rigged the vote.
Sogavare said those involved in the latest unrest had been “led astray” by unscrupulous people.
“I had honestly thought that we had gone past the darkest days in the history of our country, however… (these) events are a painful reminder that we have a long way to go,” he said.
“Hundreds of citizens took the law into their own hands today. They were intent on destroying our nation and… the trust that was slowly building among our people,” the prime minister added.
“No one is above the law… these people will face the consequences of their actions,” he said.