It’s not just the US and UK who are crying foul over China's behaviour in cyberspace - now the government of tiny Belgium has accused hackers from the country of targeting its systems.

Justice minister Jo Vandeurzen is reported to have claimed that the Federal Government had been targeted by Chinese hackers, backing up a separate statement by Belgium's foreign affairs minister, Karel De Grucht that his ministry had been hit by espionage in recent weeks.

In both cases, the Belgians appear certain that the culprits were Chinese and that the Beijing authorities must know something about events, although no evidence has been offered to back up these allegations. The precise nature of the attacks has not been explained either.

If the accusation is justified, it is starting to look as if Chinese-originated cyber-attacks have spread well beyond the obvious Western targets.

The Chinese have been implicated in acts of cyber-espionage in the last couple of years, including various alleged assaults on US military systems in 2006 and 2007. As recently as last September, a "leaked" report blamed the Chinese for a similar attack on the Pentagon.

The US reports have come in the form of briefings from unnamed individuals or leaks, suggesting that the US was sending a coded warning to the Chinese that such events risked damaging relations between the countries.

The UK, by contrast, has been more pointed. In late 2007 it openly sent letters to large UK companies warning them of the threat from Chinese-backed cyber-warfare.

"There simply isn't enough evidence to say whether these attacks were sponsored by the Chinese Government or not," said Graham Cluley of Sophos on the Belgian attacks.

"Governments need to think carefully before accusing another of spying via the Internet - unless they have strong proof. There is no doubt however of the importance of securing critical computers inside government from hackers whether motivated by politics, espionage or money," he added.