Locusts are mating in Kenya, which means more of the pests will be causing havoc
The invasion of locusts in East Africa is likely to cause the region's worst humanitarian crisis in recent times, an international charity says.
A second invasion is due in the next few weeks, Mercy Corps added.
The recent arrival of locusts in South Sudan was especially worrying, as more than half the population already relied on humanitarian aid, it said.
The insects are ravaging crops and pastures in parts of East Africa where tensions over grazing land are already high.
Experts say the numbers of the fast-breeding creatures could grow by 500 times before June when dry weather sets in, which helps curb their spread.
The pests consume their own body weight in food every day.
The UN's food agency says this is the worst locust invasion in East Africa in 25 years.
