A major blackout hit most of Tanzania on Saturday as heavy rains and strong winds from Cyclone Hidaya lashed the country following weeks of flooding in the region.
Ferry services between Tanzania's commercial hub, Dar es Salaam, and Zanzibar were suspended as Cyclone Hidaya approached the East African coast with maximum winds of 120 kph (33 mph) and powerful gusts.
Authorities warned residents to exercise caution as the intensity of the cyclone increases.
The weather service said more than usual amounts of rainfall were recorded in coastal areas overnight. The Tanzania Red Cross Society has been carrying out preparedness campaigns along the coast.
In the past few weeks, flooding in Kenya and Tanzania killed hundreds after heavy rain during the region's monsoon season, officials said. Flooding in Tanzania killed 155 people and affected more than 200,000 others, the prime minister said in April.
In Kenya, 70 people have died since the start of monsoon season in March, a government official said.
The East African region is highly vulnerable to climate change. El Niño is expected to last through the spring. The region's dry season typically begins in June.