TOKYO — Japanese Prime Minister Shinzo Abe defended his policy toward terrorism, as the flag at his official residence flew at half-staff today in a mark of mourning for two hostages killed by the Islamic State group.

During a long day of parliamentary debate, Abe parried numerous questions about his handling of the hostage crisis, which came to a grisly end with news early Sunday that journalist Kenji Goto had been beheaded by the extremists.

Abe said his announcement of $200 million in nonmilitary aid for the fight against the Islamic State group, made during a visit to the Middle East just days before the militants demanded a $200 million ransom for the two hostages, was meant to convey Japan's strong commitment to battling terrorism and fostering peace and stability in the region.

Some have questioned that decision, saying Abe should have been more cautious and not mentioned the Islamic State group by name.

MONROVIA, Liberia — A large-scale human trial of two potential Ebola vaccines got under way in Liberia’s capital today, part of a global effort to prevent a repeat of the epidemic that has now claimed nearly 9,000 lives in West Africa.The trials in Liberia are taking place after smaller studies determined that the vaccines were safe for human use. By comparing them now with a placebo shot, scientists hope to learn whether they can prevent people from contracting the ghastly virus that has killed some 60 percent of those hospitalized with the disease.Authorities still must combat fear and suspicion that people could become infected by taking part in the trial.