Israel on Sunday offered assistance to Nigeria in locating 276 high-school girls still held after being abducted four weeks ago by the Boko Haram terrorist network.The offer came as Prime Minister Binyamin Netanyahu spoke from Japan Sunday to Nigerian President Goodluck Jonathan.“Israel expresses its deep shock at the crime committed against the girls,” he said.“We are willing to help assist in locating the girls and fighting the terror that is afflicting you.”For weeks Jonathan has refused international assistance to help locate and free the girls, and only agreed to accept help from the United States, France, Britain and China last week.Nigeria is one of Israel’s closest friends in Africa, and Israel provided Nigerian authorities with medical supplies following a Boko Haram attack against three churches on Christmas Day in 2011 that killed dozens.Last September, Israel was among several countries that sent advisers to Kenya to assist in a stand-off with Islamist gunmen who attacked a mall in Nairobi.