A powerful Philippine clan¹ leader suspected of involvement in the massacre² of 57 people has been taken into custody³, officials said.

一位有权势的菲律宾氏族首领因涉嫌参与57人的大屠杀而被拘押。

A state of emergency was declared in Maguindanao province

Andal Ampatuan Jr had surrendered to authorities, they said. He denies organising the killings⁵, AFP reported.

Earlier, troops and police swooped⁶（抓取，突然袭击） on towns on the southern island of Mindanao run by the Ampatuan family.

The massacre took place on Monday as a convoy⁷（护送，护卫） of vehicles used by a rival politician was ambushed⁸（埋伏）.

The group, involved in activities for the 2010 elections, was taken to a remote hill region, shot at close range and their bodies dumped in shallow graves.

Taken by helicopter

Interior Secretary Ronaldo Puno said that Mr Ampatuan Jnr was taken by helicopter from his hometown in the restive⁹（倔强的，难驾驭的） Maguindanao province on Thursday morning to a nearby airport.

From there he was being flown to the capital Manila for questioning, Mr Puno said.

Police were reported to have rounded-up and disarmed¹⁰ a 200-member paramilitary force in Maguindanao on Thursday. They also made several arrests.

Officials named militiamen under the control of Mr Ampatuan Jr - the mayor of a town in Maguindanao - as suspects.

All police officers from one town are under investigation¹¹ for the killing⁴, AFP news agency reported, citing government officials.

Although prominent（杰出的，显著的） members of the Ampatuan family are allies of President Gloria Arroyo¹², they have been expelled from her party since the killings.

President Arroyo, who earlier declared a national day of mourning, has promised that the gunmen would not escape justice.

The BBC's Danny Vincent, in Manila, says the Ampatuans have been involved in a long-standing feud¹³（不和，争执） with a rival family who want to oppose them in the national and local elections.

Philippine politician Ismael Mangudadatu has claimed it was gunmen loyal to the Ampatuans who ambushed his supporters as they were travelling to register his name for the polls.

Among the dead were Mr Mangudadatu's wife, his two sisters and several key supporters, as well as at least 13 journalists who were travelling with them to witness his registration¹⁴ as an election candidate.

Analysts¹⁵ say the Ampatuans have effectively been in charge of Maguindanao for decades.

Andal Ampatuan Snr has served in the Philippines Congress and won the governorship of Maguindanao unopposed for several terms.

His son was reportedly planning a similarly unopposed run to replace his father but then Mr Mangudadatu decided¹⁶ to run as well.