Longstanding tensions between China and Taiwan have erupted over a physical fight between their diplomats in Fiji.
Taiwan alleges two Chinese embassy officials gate-crashed an event to celebrate their national day earlier this month - claims Beijing disputes.
Both sides say their officials were injured in the fight, and have asked Fiji police to investigate.
China regards Taiwan as a breakaway province but Taiwan's leaders argue it is a sovereign state.
Relations between the two are frayed and there is the constant threat of a violent flare up that could drag in the US, an ally of Taiwan.
The latest incident is said to have occurred on 8 October as Taiwan's trade office in Fiji - its de facto embassy - held a reception for some 100 distinguished guests in the luxurious Grand Pacific Hotel in the Fijian capital Suva.
Taiwan's foreign ministry claimed two Chinese officials began taking pictures and trying to collect information about the guests. The Taiwanese diplomat who asked them to leave was assaulted and needed hospital treatment for a head injury, the ministry said.
"We strongly condemn the actions by the Chinese embassy in Fiji staff for seriously violating the rule of law and civilised code of conduct," Taiwan foreign ministry spokeswoman Joanne Ou said.
China gave a different account of events. Its embassy in Fiji said its staff had been in a "public area outside the function venue" carrying out unspecified "official duties" and accused Taiwanese officials of acted "provocatively" and causing "injuries and damage to one Chinese diplomat".
China's foreign ministry, in a briefing on Monday, revealed its officials were aware of what was happening inside the venue, including the fact there was a cake featuring the Taiwanese flag, which Beijing describes as false because it does not recognise Taiwan as a country.
"A false national flag was openly displayed at the scene, the cake was also marked with a false national flag," spokesman Zhao Lijian was quoted by AFP news agency as saying.
Fijian police have made no comment on the investigation.
Beijing has long tried to limit Taiwan's international activities and both have vied for influence in the Pacific region.
Although Taiwan is officially recognised by only a handful of nations, its democratically-elected government has strong commercial and informal links with many countries.