Castaways stranded on two separate boats in a remote part of the north Pacific ocean are reported to have been rescued after they were spotted by a helicopter pilot scanning for tuna.

The Marshall Islands Journal says both vessels were from the central Pacific island nation of Kiribati, more than 600km (370 miles) away.

One had three fishermen on board and had been adrift for almost a month.

A 14-year-old boy on the other boat was reported to have been lost for 11 days.

The crew of the fishing boat survived by eating tuna and shark and drinking fish blood, the Journal reported.

Image copyright AFP Image caption The stranded sailors have been taken to the Marshall Islands, about 600km away from where they were rescued

Ocean currents brought the two boats to within 8km of each other but they are said to have been unaware of the other's presence until they were rescued by a fishing vessel and taken to the Marshall Islands.

The teenager's boat was pulled away by strong currents as he tried to bring it closer to land, the Marshall Islands Journal reported. It had been moored close to a coral reef and his uncle wanted it out of the way of a rising tide.

The paper says the child became so thirsty he was forced to drink sea water.

The three fishermen drifted for at least 28 days in a 15ft wood boat, the paper said, with one crew member suffering from acute dehydration.

The vessel's engine - which earlier had broken down - ran out of fuel after it was repaired, the paper reported.