Hundreds of fishermen from Pakistan and India are arrested every year by each others' maritime security forces for allegedly trespassing. But most of them do not have proper navigation tools, and the waters are not divided by a physical boundary.
Obtaining their release is difficult and many are left in prison for years, because of long-running tensions between the countries.
Al Jazeera's Imtiaz Tyab reports from Karachi.
Source: Al Jazeera