At least five people were killed and one severely injured in a tanzanite mine collapse in northern Tanzania, police said on Sunday.

Regional police commander Akili Mpwapwa said the deadly mine accident occurred on Saturday night in the area of Mireran in Manyara Region,

He said the accident occurred at midnight when miners were searching for the tanzanite underground -- a purple-blue shimmering stone.

The mine involved in the accident is owned by Fanoni Mining Ltd, a property of Onesmo Mbise.

Mpwapwa said five miners were dead and one survived in the accident with serious injuries and was admitted at the Kilimanjaro Christian Medical Center (KCMC) in Moshi Municipality.

The mine accident followed another one in northern Tanzania, in which 14 people were killed on April 1 in the area of Moshono of Arusha.

Tanzanite, a gemstone discovered by Maasai tribesmen in 1967, is found only in northern Tanzania. In 2005, a leading gemstone miner said it unearthed the world's largest tanzanite stone weighing about 3 kg.

The lure of striking riches has drawn thousands of miners to Mirerani, which resembles a gold-rush town dotted with brothels, bars and hardware stores supplying the miners.

Tanzanite is believed to be limited to East Africa's Rift Valley. The pits where the accident happened are located in the heart of Maasai, a short distance from Mount Kilimanjaro.

The East African nation's mining sector has expanded rapidly over the past decade after it adopted liberal economic policies in the mid-1980s.

Tanzania, the continent's third-largest gold producer after South Africa and Ghana, is also rich in diamond, emerald, ruby and sapphire.

The mining sector contributes less than 3 percent of the nation's GDP, but the rate could reach 10 percent by 2025, according to a development plan outlined by the government.