Philippine President Rodrigo Duterte [BBC profile] declared martial law on the island of Mindanao on Tuesday when heavily armed militants linked to the Islamic State [BBC profile] took over large parts of Marawi City, a provincial capital in the predominantly Roman Catholic country. Violence erupted after the government attempted to capture [WP report] Isnilon Hapilon, the leader of the Muate, a militant group that aligns with the Islamic State. The militants have been [Reuters report] capturing Christians, setting prisoners free, and seizing and torching buildings. The measures under martial law will apply the entire island, affecting nearly 21 million people, and will include curfews, the establishment of checkpoints and the suspension of the writ of habeas corpus. The martial law declaration has raised suspicions as to whether Duterte has other motivations, as he has raised the prospect of martial law several times in connection with his deadly attempt to suppress drug sales in the Philippines. Duterte, who was scheduled to meet with Russian President Vladi­mir Putin and Prime Minister Dmitry Medvedev [BBC profiles], has cut his trip to Moscow short to return to Manila to address the current crisis.

More than 8,000 people have reportedly been killed over drug-related offenses since Duterte took office last year. Numerous rights groups have been critical of the killings and have spoken out against the current administration. Early in March Human Rights Watch [advocacy website] released a report that accused the police of falsifying evidence [JURIST report] in relation to the alleged police killings of citizens. This policy of sanctioned killings has been part of Duterte’s rhetoric since his time as mayor of Davao City. In December a UN Human rights chief called for a murder investigation [JURIST report] after Duterte admitted to killing people in his role as mayor.