The Australian navy said Saturday it seized and destroyed 353 kilograms of heroin with an estimated street value of more than Aus$700 million (US$627 million) in a mission off the coast of Tanzania.

HMAS Melbourne discovered the haul when crew boarded a vessel on Wednesday as part of a mission "in support of deterring terrorism and promoting peace and security in the maritime regions of the Middle East and Indian Ocean".

The elephant population in Tanzania, beset by poaching for ivory, has plummeted by two-thirds in the past three-and-a-half decades, the government said on Saturday.

The findings are the result of a census carried out at the end of last year in the country's parks and reserves with the largest elephant herds, Lazaro Nyalandu, junior minister for natural resources and tourism, said in a statement.

Tanzania on Friday fired four key ministers for abuses committed by the security forces during a controversial anti-poaching drive, the Prime Minister said.

The officials fired are Defense Minister Shamsi Vuai Nahodha, Interior Minister Emmanuel Nchimbi, Natural Resources and Tourism Minister Khamis Kagasheki and Lifestock and Fisheries Minister David Matayo. All four are from the ruling party.

An Ethiopian Airlines jet got stuck at a small airport in northern Tanzania, after it made an unscheduled landing there, an Agence France Presse journalist and aviation sources said Thursday.

Arusha airport is normally used only for smaller aircraft on domestic flights and light aircraft chartered for trips to game parks.

A Tanzanian court on Tuesday ordered the release of 52 supporters of a controversial Muslim cleric, jailed earlier this year after rioting during protests calling for their leader's release.

The supporters of Sheikh Ponda Issa Ponda, head of the Jumuiya ya wa Islamu (Community of Islam in Swahili), a group not recognized by the Tanzanian authorities, were jailed in March for a year.

At least 13 people, most of them small children, drowned and seven others were missing after a boat capsized on Lake Tanganyika, Tanzanian police said Thursday.

The 11 children who drowned in Wednesday's accident, all aged between two and five, were travelling to a clinic in a nearby village in the south of the country to get vaccinated.

The president of Zanzibar on Saturday urged islanders to mobilize in the wake of two attacks that have seen British tourists and a Catholic priest doused with acid.

"We cannot continue living in fear and have people being targeted by thugs using acid," said Ali Mohammed Shein, the president of the semi-autonomous Tanzanian archipelago.

U.S. President Barack Obama Tuesday vowed an urgent effort to bring electric power to the impoverished heart of Africa, as he wrapped up a week-long journey through the continent in Tanzania.

Obama also performed a sombre double act with George W. Bush, linking up to remember victims of an embassy bombing in Dar es Salaam in 1998, a day after praising his predecessor's AIDS program as a "crowning achievement."

Tanzanian police said Saturday they have arrested five people in possession of explosives in the economic capital Dar es Salaam.

"Five people were arrested the day before yesterday (Thursday) in possession of explosives after a tip-off from patriotic citizens," Dar es Salaam's police chief Suleiman Kova told AFP.

A Tanzanian man has been charged with murder in connection with a deadly bomb attack on a church in northern Tanzania that killed three people, police said Tuesday.

Nine suspects were arrested following the May 5 explosion in Arusha, police said, including five Tanzanians, three Emiratis and a Saudi.