A Danish intelligence company specializing in maritime security says there was a dramatic increase in the number of seamen held by Somali pirates in September.

Risk Intelligence says pirates held 374 people captive after raids off the Horn of Africa last month. That compares with 292 hostages in all of 2007.

Company manager Hans Tino Hansen says hijackings have become a lucrative business for Somali pirates who make an average of $1 million per hijacked vessel.

The private group says in a report published Thursday that crews are held an average of five weeks before being released.

Hansen says the attacks can be stopped only if there “is extended political stability and a real economic development in Somalia.”