Professional networking service LinkedIn confirmed Thursday that its website had been blocked in parts of China and that it was investigating the matter.

According to Business Week, it had been reported earlier Thursday by WebSitePulse and just-ping.com — services which monitor access to websites from locations around the world — that users in Shanghai and Beijing, among other cities, were unable to access LinkedIn.

“We can confirm that access to LinkedIn is being blocked for some in China, and we are currently in the process of investigating the situation further,” Hani Durzy, a spokesman for LinkedIn, said in an e-mail, but he did not offer up a reason behind China’s decision.

However, a Chinese LinkedIn user posted comments on the site this week, questioning whether the recent revolutions in Tunisia and Egypt could be mirrored in the communist country. Those protests were organized in part via Facebook and Twitter users.

LinkedIn — which has more than a million users in China — is not the first major global social media service which the country has blocked. It has refused to allow citizens access to Twitter and Facebook since 2009, but some have been able to access those social networks through third-party proxy services.

What do you think of China’s decision to revoke access to LinkedIn?