The Philippine army has arrested more than 60 people loyal to the governor of the southern province of Maguindanao.

The authorities say 15 of the detainees were arrested at a ranch belonging to Governor Andal Ampatuan. The army also seized a huge cache of weapons. The arrests come after Manila imposed martial law in Maguindanao on Friday night in a bid to put down a rebellion by the powerful Ampatuan clan.

The family has ruled the province for 10 years and the authorities say the Ampatuans were behind the murders of 57 members of a rival political clan on 23 November. Around 100 Ampatuan gunmen allegedly kidnapped and massacred relatives of a rival politician along with journalists and innocent bystanders in a remote region of Maguindanao.
 

Manila ordered the arrests after supporters of the Ampatuan clan threatened to resort to violence if members of the family were detained by police. The clan, which is allied to President Gloria Arroyo's ruling coalition, is both powerful and wealthy and has its own private army.