By Charles Haviland BBC News, Colombo

	India has thanked Sri Lanka for releasing the fishermen

The government says the large number of fishermen were apprehended after being encircled at sea by their Sri Lankan counterparts a few days ago. It denied reports that its navy was involved.

The release followed high-level meetings between Sri Lankan defence officials and Indian diplomats in Colombo.

According to the Indian news agency, PTI, the Indian foreign minister, SM Krishna, thanked the Sri Lankan government for securing these releases, and delivered an appeal to southern Indian fishermen not to stray into Sri Lankan waters.

'Unacceptable'

Despite this apparent admission of transgression by the Indian fisherfolk, Delhi was not at all happy at the earlier arrests, which the Indian prime minister described as unacceptable.

	Dr Manmohan Singh has described the arrests as 'unacceptable'

The diplomatic activity to secure their freedom overrode an earlier court order in northern Sri Lanka that the men be kept in custody for several weeks.

There is clearly some anger on both sides of the Palk Strait which separates these two countries, anger which will not be easily assuaged.

Fishermen in northern Sri Lanka recently told the BBC they were fed up with large Indian trawlers entering their waters and overfishing.

But last month villagers in southern India accused the Sri Lankan navy of killing two of their fishermen out at sea.

At the time the Sri Lankans said naval involvement was unlikely but asked for more information so that perpetrators could be brought to account.