ARUSHA: Two people were killed in Sunday's attack during a mass at a Tanzanian church, officials said Monday, as President Jakaya Kikwete called the explosion an "act of terrorism".
Six people have been arrested, including four from Saudi Arabia, officials said.
"This is an act of terrorism perpetrated by a cruel person or group who are enemies of the country," Kikwete said in a statement, condemning the bombing in the northern Tanzanian town of Arusha in which at least 30 people were also wounded.
Such a large scale attack targeting a church is one of the first such incidents in Tanzania.
Arusha's commissioner Magesa Mulongo confirmed that two people had died and that six people had been arrested, two from Tanzania and four from Saudi Arabia.
"Investigations are ongoing," Mulongo said, adding that the four Saudis had arrived at Arusha airport on Saturday.
The two Tanzanians arrested were Christian, he added, but gave no further details.
The blast took place outside a Roman Catholic church in Arusha, a town popular with tourists visiting the famous Serengeti national park and snowcapped Mount Kilimanjaro.
Officials have given no indication as to who might have carried out the attack, but tensions have been high between Tanzania's Christian and Muslim communities in recent months.