"We understand that the freedom of reporting, news gathering and travel should be respected as much as possible, but at the same time the government has the extremely important duty of ensuring the safety of Japanese citizens who travel or live abroad," Suga said as quoted by Kyodo news agency. "Two Japanese were detained and killed by ISIL [Islamic State in Iraq and Levant, IS] only recently and ISIL has also warned it will try to kill more Japanese."
Suga added that decision to confiscate Sugimoto's passport was made after careful consideration of the circumstances.
The IS is a radical Sunni group known for its brutal tactics, such as public crucifixions and beheadings of captured prisoners, including journalists.
In late January, IS militants threatened to kill two Japanese nationals — security expert Haruna Yukawa and freelance journalist Kenji Goto — if Tokyo did not pay a $200-million ransom. The extremists have fulfilled their pledge, uploading videos of the beheadings.