US forces in Okinawa are to be put under night-time curfew for a month following the suspected rape and murder of a woman by a former US marine, officials said Saturday. The announcement, part of a one-month “period of unity and mourning” comes after US President Barack Obama expressed his “deepest regrets” over the killing. Public anger boiled over last week after police arrested a former US Marine, now a base employee, in connection with the death of the 20-year-old woman, who had been missing since late April. The 30-day period would involve a night-time curfew and other “modified liberty regulations”, Lawrence Nicholson, the head of US forces in Okinawa, announced. “This period of unity and mourning will include the postponement of all festivals, celebrations and concerts on our bases and stations,” he told a press conference in Okinawa. The island was the site of a World War II battle and is now considered a strategic linchpin but the heavy US military presence has long been a thorn in the side of the two countries’ relations. It hosts the lion’s share of US bases in Japan and more than half the 47,000 American military personnel in the country under a decades-long security alliance. A series of crimes including rapes, assaults and hit-and-run accidents by US military personnel, dependants and civilians have long sparked local protests on the crowded island. Obama at a joint press conference on Wednesday with Japanese Prime Minister Shinzo Abe, who had earlier expressed indignation over the case, extended his “sincerest condolences and deepest regrets”. “The United States will continue to cooperate fully with the investigation and ensure that justice is done under the Japanese legal system,” said Obama, who was visiting Japan to attend the summit of the Group of Seven rich nations.