In 2009, 58 people - 32 of them journalists - were killed when their convoy was attacked in the southern province of Maguindanao.

Five members of the clan, including brothers Andal Ampatuan Jr and Zaldy Ampatuan, were sentenced to life in prison. A third brother was acquitted.

The case was seen as a test of the integrity of the justice system.

It comes amid claims by rights groups that impunity for powerful politicians is on the rise in the country, says the BBC's Howard Johnson in Manila.

Three other members of the clan - Anwar Ampatuan Sr, Anwar Ampatuan Jr, and Anwar Sajid Ampatuan were also found guilty.

The Ampatuans deny all charges and said they would appeal against the verdict.

Other suspects, who were ordered by the Ampatuan family to carry out the killings, received sentences of between six to 10 years in prison.

About 80 other suspects remain at large, including police officers and Ampatuan clan members.

Many accused police officers were acquitted.

What happened in Maguindanao?

The restive province of Maguindanao had for years been governed by the Ampatuan family, who occupied almost all the political posts in the area.

But in the elections for provincial governor, a rival from another influential clan emerged - Esmael Mangudadatu.

On Nov 23 in 2009, a convoy of vehicles carrying the wife, sisters and other female relatives of Mr Mangudadatu set out to register their candidate for the poll.

A group of 32 journalists and media workers were also there to capture the event - a total of 58 people were present.

Their convoy was kidnapped by henchmen allegedly sent by members of the Ampatuan clan, who ordered them brought to a hilltop and shot.

Their bodies were found in a mass grave.

"My wife was shot 17 times. They shot her breasts, her private part. I cannot just forget that," said Mr Mangudadatu, who went on to be elected the governor of Maguindanao.

Rights group Amnesty International called Thursday's verdict a "critical step towards justice".

However, it said the "search for justice is far from over" and called for the government to "dismantle private armies that underpin the power of political clans". – BBC/AP