A woman and four children died after a stampede while Tanzanians mourned former President John Magufuli, police told the BBC.
Some reports say the death toll could reach 40, but officials have not confirmed this.
Tens of thousands of people came to a stadium in Dar es Salaam to see the body of the former president.
Nicknamed a bulldozer, Mr. Magufuli was popular with many Tanzanians for his rational governance style.
Critics, however, accused him of being an autocrat and repressing dissidents.
He also minimized the effects of the coronavirus and stopped publishing the country’s case and death figures. Opposition politicians say Magufuli died from Covid-19, but this has not been confirmed.
‘Overwhelming pain’
Dennis Mtuwa’s wife, two of his sons, a nephew and a niece were confirmed among the dead after Sunday’s stampede, reports the BBC’s Salim Kikeke of Dar es Salaaam.
“These past 24 hours have been really difficult for me. I feel relieved when I’m surrounded by people, but when I’m alone the amount of grief becomes unbearable,” Mtuwa told the BBC.
The city’s police commander, Lázaro Mambosasa, said he would give more details on Tuesday.
On Monday, thousands of Tanzanians attended the state funeral of Magufuli in the capital, Dodoma, in the presence of several African leaders who paid enthusiastic tributes.
The continent was “saddened by the death of a revolutionary,” said Felix Tshisekedi of the Democratic Republic of Congo about Magufuli, who died last week after heart complications at age 61.
Tanzania’s new president, Samia Suluhu Hassan, remembered his predecessor as an advocate for the poor and a religious man.
“He was not only our leader, but also a guardian and father of many … and an honest man,” said President Samia.
Tanzanian leaders who attended the funeral and most of the thousands of people at the stadium in Dodoma did not wear masks or observe social distance – health measures that the late president often scoffed at.
However, visiting leaders and other delegations wore masks.
He will be buried in his hometown, Chato, in the northwest, on Friday.
What did African leaders say?
The president of Mozambique, Filipe Nyusi, said that the former president of Tanzania “will stay in the hearts” of many.
In his honor, the president of Malawi, Lazarus Chakwera, referred to Magufuli as “the best son in Africa”, whose “life of service” would be remembered.
South African President Cyril Ramaphosa described him as a “true pan-Africanist” who did not apologize for being African.
Mr. Ramaphosa remembered the former president as a “warrior” against corruption and who worked for his people.
He also said that the president of Tanzania is a champion of African culture and traditions, especially the use of Swahili, the lingua franca of East Africa, across the continent.
“Swahili was introduced to schools in South Africa as an honor to the late President John Magufuli, who insisted on its use,” said Ramaphosa.
This was echoed by the president of Botswana, Mokgweetsi Masese, who said that Mr. Magufuli was a “great teacher”, like the founding president of Tanzania, Julius Nyerere.
“Even in Botswana, he expected us to speak Swahili … We also introduced Swahili into our resumes.”
In his honor, the president of Kenya, Uhuru Kenyatta, also addressed Mr. Magufuli’s successor, saying: “For you, my sister and now my counterpart, the path has been shown to you by our brother President Magufuli.”
“The Democratic Republic of Congo and the African Union together are saddened by the death of revolutionary Dr. John Magufuli. We are praying for the Tanzanians. The Democratic Republic of Congo is with you in this difficult period,” said President Tshisekedi, who is the current president of the African Union.