HYDERABAD - Leaders of the world's press held a moment of silence at the start of an annual meeting on Tuesday to mark the murder of several journalists in a Philippine massacre.

The killings were "an act of savagery that has written one of the blackest pages in the history of the world's press", said Gavin O'Reilly, president of the World Association of Newspapers and News Publishers.

The association said 30 journalists and their support staff were among the 57 people killed in the November 23 attack on a political convoy in the southern Philippine province of Maguindanao.

Philippine reports have said at least 18 journalists were killed.

Indian President Pratibha Devi Singh Patil stood in silence with several hundred publishers, chief editors, managing directors and other senior newspaper executives attending the 62nd World Newspaper Congress in the southern Indian city of Hyderabad.

The massacre was allegedly carried out by armed men working for a powerful local political clan.

The deaths took the number of journalists killed worldwide so far this year to 88, according to a report released by the world association at the Hyderabad meetings.

Hundreds more have been arrested and jailed, "most often following sham trials", and at least 170 are currently behind bars, the report said.

In Asia, the report cited the continued imprisonment of journalists in China, Myanmar's mass censorship and repression of independent media, as well as violence against the press in Sri Lanka and Nepal.

It also criticised governments throughout the Middle East and North Africa for demonstrating an "intolerance for truth, dissent and satire".

The report further accused numerous African leaders of abusing criminal defamation and sedition laws to punish journalists who expose policy failures and corruption.