Pakistan on Sunday released 86 Indian fishermen held for trespassing into its territorial waters, officials said.

Pakistan on Sunday released 86 Indian fishermen held for trespassing into its territorial waters, officials said, the second batch freed this month.

"We released 86 more Indian fishermen today," Superintendent of Karachi's Malir prison Raja Mumtaz told AFP, adding that 363 still remain in Pakistani custody.

On March 6, Pakistan released 86 fishermen and a civilian prisoner, he added.

Indian and Pakistani fishermen are frequently detained for illegal fishing since the Arabian Sea border is not clearly defined and many boats lack the technology to fix their precise location.

The fishermen often languish in jail, even after serving their terms, as poor diplomatic ties between the two arch-rivals slows up bureaucratic requirements for release.