Mozambique police have arrested four men accused of running a kidnapping ring behind more than 20 abductions in the capital Maputo in the past year.
The alleged ring-leader, Bakhir Ayoob, is the son-in-law of Mohamed Bachir Suleman, a wealthy businessman in the city. Washington has branded Suleman a drug kingpin and in 2010 banned U.S. companies from having any financial dealings with him.
Wealthy Muslims have been the main targets of the kidnappings, which began in November. All those abducted were released after ransoms were paid.
When a 17 year-old girl was kidnapped last month, Muslims in the city threatened to strike in protest at what they said was a lack of government action.
Police detained Ayoob, 30, at his home early on Friday. He is the highest-profile suspect of 20 men arrested in connection with the kidnappings.
The abductions are part of a wider crime wave targeting wealthy foreigners who have moved into Maputo on the back of a flood investment into the southern African nation's vast coal and natural gas reserves.