Pakistan on Sunday released 220 Indian fishermen held for trespassing into its territorial waters as a “goodwill gesture” to New Delhi, officials said.

“We released 220 Indian fishermen today as a goodwill gesture,” Deputy Superintendent of Karachi's Malir prison Hassan Sehto told AFP, adding that 219 others still remain in Pakistani custody.

The freed fishermen are expected to cross over into India on Monday.

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 neighbours mean fulfilling bureaucratic requirements can take a long time.

Tensions simmer between Pakistan and India following an alleged 'surgical strike' and the Uri army base attack earlier this year as the two locked horns over Kashmir following a crackdown against protesters in India-held Kashmir after Hizbul Mujahideen commander Burhan Wani was killed by government forces in July.

The Indian deputy high commissioner has been summoned to the Foreign Office several times to protest intermittent 'unprovoked' ceasefire violations across the Line of Control and Working Boundary.

Indian Prime Minister Narendra Modi stepped up a drive to isolate Pakistan diplomatically after the Uri army base attack and India has termed Pakistan a 'terrorist state'.