The U.N.’s Office for the Coordination of Humanitarian Affairs said in an update that 13 humanitarian workers were abducted in the first 27 days of April. The highest monthly figure since 2011.
The U.N. reports more than 30 violent incidents in Somalia in April which affected humanitarian organisations.
This is almost equal to the total for the first three months of 2017.
The aid body is racing to avoid a repeat of the 2011 famine in the drought-hit country, when more than 250,000 people died of starvation.
An estimated 2.9 million people in Somalia are facing famine.
The UN says convoys of up to 60 commercial and aid trucks have been stranded for more than a week after local authorities demanded high amounts of unjustified extortion.