China has reacted with external defiance and domestic calm following Tuesday’s historic ruling about jurisdiction in the South China Sea.

It used international social media to challenge the ruling and may have blocked Chinese access to some international media reports following the verdict.

The judgement in The Hague saw The Philippines take its territorial dispute with China to a panel of international judges for arbitration. The unanimous ruling on Tuesday found largely in favor of The Philippines.

China has spent several weeks warning that it gives no credibility to the UN tribunal and that it would not be bound by its findings.

The judgement was announced on Tuesday morning, and late afternoon in China. Shortly afterwards, one source reported that the BBC had gone offline in China, seemingly having been shut out by Chinese censors.

Another reported that searches on Weibo social media had become unstable.

The People’s Daily used its Weibo account to say: “Don’t accept. Don’t participate. Don’t recognize. Don’t carry out.”

English language versions of other official Chinese media used Twitter – which is permanently blocked within China – to voice its displeasure to international audiences. “Null and void: ill-founded award on #SouthChinaSea arbitration issued xhne.ws/Sam5b” said official news agency Xinhua.

GreatFire.org, an organization that monitors the Internet in China, reported that web page of the UN’s Permanent Court of Arbitration, which handed down the 501-page ruling, had become inaccessible.

The tribunal ruled that China had no historical basis for its claims over the waters of the South China Sea. China makes claim to 90% of the Sea, some of which is nearly 2,000 km from its continental coast. It demonstrated its claim by what it has called a ‘nine dash line’ on maps of the Sea.

The tribunal rejected the nine dash line and said that there was “no evidence that China had historically exercised exclusive control over the waters or resources.”

In the past four years China has taken control of several rocky outcrops, low water elevations and reefs in the disputed area.

By extending the landmass of some of these, and by building runways and missile installations, it has sought to project its military positions and expand its area of economic control. Reuters reported that China had Tuesday carried out calibration exercises at the new airports.

China’s Foreign Ministry issued an English-language statement which made no mention of the tribunal, but instead reasserted its historic rights and 2,000 years of activity in the area.