The attacker, identified by officials as Hamza Mohamed, went on a rampage on August 25. He killed three police officers and a private security guard before being shot by police. Six other people were also injured in the incident, which unfolded just outside the entrance to the French Embassy.

"Our investigations have revealed that Hamza Mohamed was a person who had a secret life with all indicators of terrorism," the director of criminal investigations, Camillus Wambura, told journalists on Thursday.

Wambura said Mohamed was one of the "type of terrorists who are ready to die for their religion," but did not identify any religion associated with the attacker. The gunman also communicated with "other people who live in countries with terrorism-related acts but mainly he was learning through radical social media pages," he added.

The director of criminal investigations also said that the assailant "spent much of his time" browsing the internet to "learn" about the terrorist attacks launched by Islamic State (IS, formerly ISIS) and Al-Shabaab, another terrorist group, active in East Africa and Yemen. A local group, which also bears the name Al-Shabaab, is active in Mozambique, which borders Tanzania.

Tanzania's Police Inspector-General Simon Sirro earlier suggested that the attack might be linked to the government's decision to send troops to neighboring Mozambique, where Islamist insurgents are fighting the army. - RT