The website of China's top agency for handling official complaints crashed temporarily on Monday, when its full online service was launched.

The State Bureau for Letters and Calls had announced on Friday that its website would be able to handle complaints as of Monday.

However, many netizens complained on Monday morning that they were unable to register on the bureau's website before filing online complaints.

Registration at the website was unavailable for most of the day, and it was inaccessible for around 30 minutes.

The bureau, which handles complaints about civil servants and village officials, was unavailable for comment on Monday.

It opened an online channel for petitioners to submit complaints on agriculture-related issues on Jan 1, 2009.

The purview of the online channel was expanded the following year to cover issues such as forced demolitions.

Shu Xiaoqin, the bureau's chief, said at a conference on Friday that the online platform would allow petitioners to submit their complaints without leaving their homes.

The bureau will enhance its website's capacity to allow more hits and guarantee that all complaints can be submitted online, she said.

Many petitioners repeatedly travel to Beijing to file complaints since grassroots officials refuse to handle them.

There are some reports that petitioners are sometimes prevented from reaching the bureau and filing their complaints, which are often related to the corrupt activities of government officials.

In January 2009, then-premier Wen Jiabao inspected the bureau and met petitioners.

Wen, in the first visit by a premier to the bureau, called on its officials to be more responsible and dedicated to addressing complaints.

A survey by China Youth Daily in January 2012 showed that 70.5 percent of petitioners were unsatisfied with the bureau, saying that its officials should do more to address real problems.

Ma Huaide, vice-president of China University of Political Science and Law, said that the bureau should keep its promise to reply to every complaint, and more efficiently deal with the issues raised by petitioners.

Many petitioners travel thousands of kilometers to file their complaints in Beijing, as they believe that the central authorities will give them a fairer hearing than local officials, said Ma.

But the bureau's function is to transfer petitioners' complaints to government agencies, and it is unable to directly resolve disputes, he said.

The ultimate solution is to promote the rule of law, he said.