The Philippines government has imposed martial law in one of its southern provinces after 57 people were massacred last month.Police arrested five members of the Ampatuan political clan – including the patriarch and the governor of Maguindanao – who are suspected of masterminding the killings. Lt Gen Raymundo Ferrer, who has taken charge of the province, said: “We expect to make more arrests, because we are looking at about 100 (people) involved in that heinous crime.” In Maguindanao province, and the Philippines’ capital Manila, there were protests against the lifting of civil rights for the first time in three decades. Opponents fear there could be widespread human rights violations. The Ampatuan family has ruled Maguindanao for almost ten years. Officials say the discovery of big weapons caches on Ampatuan property hardened their resolve to impose martial law. The Ampatuan clan is suspected of the Philippines’ worst ever atrocity linked to elections. On November 23, a convoy carrying a rival politician was attacked as he travelled to register his candidacy in next May’s ballot.