Chinese will soon be barred from bringing grievances directly to the central government, state-run media said Thursday, amending a longtime practice of "petitioners" seeking official redress.

The State Bureau for Letters and Calls in Beijing will no longer accept most complaints against local or provincial officials as of May 1, the China Daily reported.

It is unclear, however, if the move will deter desperate petitioners who have long seen Beijing as a last resort after their calls have gone unheeded at the local level.

Millions of Chinese "petition" government authorities at various levels every year, in a practice dating from imperial times, over disputes and grievances ranging from land grabs to police abuse.

But many local governments work to prevent complaints being filed against them in the capital, to preserve their area's image and their own career prospects.

In one notorious case, a petitioner in Shanghai was allegedly beaten to death by local police last year over a property dispute, triggering protests in the heart of the commercial hub.

Beijing has announced other measures aimed at reforming the long-troubled petition system which have faced trouble in implementation.

Last month the ruling Communist Party said government bodies must not block "normal petitioners" from seeking to report corruption to national authorities.

But officials in the central province of Henan this month sent teams to surround a hotel where officials from Beijing were staying, to block residents from telling them about corruption, the state-run Global Times reported.

Henan authorities were also found to have detained petitioners despite official vows to halt the practice.

Zhang Enxi, spokesman for the State Bureau for Letters and Calls, told the official Xinhua news agency Wednesday that the purpose of the latest regulation "is to clarify the jurisdiction, regulate the procedure and improve the efficiency of handling petitions".

"It is expected to help citizens file petitions in a stepwise manner," Zhang said.

Xinhua noted that "a few exceptions are left at the central level".

They include "complaints about corrupt officials of provincial and central governments, petitions about issues that should be addressed across provinces and sectors, as well as those that are not properly handled by provincial governments".