Hurt by slower-than-expected performance of construction, transport, agriculture and the financial services sectors, the Tanzanian growth has slowed to 5.7 percent in the first quarter of this year. Growth in the same period of 2016 was 6.8 percent.

The state-run National Bureau of Statistics (NBS) said the construction sector grew 8.4 percent in January to March, compared with 8.9 percent a year ago, while transport and storage grew 4.1 percent from 7.9 percent previously.

"During the period under review, mining and quarrying increased at the highest growth rate of 35.3 percent followed by information and communication at 13.8 percent," it said.

NBS attributed the surge in growth of the mining sector to increased production of gold, tanzanite, copper and coal.

Agriculture sector growth edged down 2.6 percent in the first quarter compared with 2.7 percent a year ago, while growth in the financial intermediation and insurance services sector also slowed to 8.1 percent from 13.5 percent a year ago.

Tanzania projects its economy to grow 7.1 percent this year from 7.0 percent in 2016, making it one of the fastest-growing in Africa.