The pain is unbearable for Komakichi Okamura who lost his 32-year-old son Makoto Okamura to Friday's savage attacks on a restaurant in the capital.

Makoto is one of the seven Japanese nationals who died in the militant siege. One survived with a gunshot wound. All eight were working for three Tokyo-based consulting firms on a Japanese government-funded infrastructure project.

"This is something so unbearable as a parent. I have no idea how I can face him, to be honest,” Komakichi told the Japanese media in front of his house yesterday.

He said he told his son to be careful before he left. "That was the last conversation I had with him on the telephone."

"He was friendly and kind to everyone, such a good boy."

Fumie Okamura, the mother of Makoto, told TV Tokyo that her son's death was devastating.

"I keep thinking why he had to 'go ahead' (die) before his parents."

Another victim, Koyo Ogasawara, worked for Katahira and Engineers International -- a transportation consultancy that has worked on projects in Southeast Asia, Africa and Latin America.

Tomaoki Watanabe, who was hospitalised after being shot, was one of four employees from Almec Corp, a transportation consultancy with offices in Manila, Hanoi, Jakarta and Ulan Bator, according to its website. The three others -- Yuko Sakai, Rui Shimodaira and Makoto Okamura -- perished.

Among those killed in the terrorist attack were three men related to Oriental Consultants Global Co, company President Eiji Yonezawa said.

Oriental Consultants is part of a Japanese project to build three bridges for the widening of the national highway from Dhaka to Chittagong. The three have been identified as Hideki Hashimoto, Nobuhiro Kurosaki and Hiroshi Tanaka.

“An employee who died in the terrorist attack was a veteran engineer, who was a precious staff member of our company. I'm very sorry and feel resentment,” Yonezawa said, expressing his anger in a choked-up voice and wiping away tears.

"We feel very indignant toward the perpetrators, because these people were working hard for the development of Bangladesh," said Shinichi Kitaoka, the president of the Japan International Cooperation Agency. He pledged to strengthen security precautions while continuing to contribute to Bangladesh's development.