The boats are carrying 40 activists, 200 hearing aids and 5,000 balloons
Two boats carrying members of a US-based pro-Palestinian group have arrived in the Gaza Strip, despite an Israeli blockade of the territory.
Israel earlier said they would be let in, saying they would not be given the chance to have a "provocation at sea".
The boats left the port of Larnaca in Cyprus on Friday morning.
The Free Gaza protest group said about 40 activists from 14 countries were on board the boats to highlight the plight of Palestinians in Gaza.
Israel imposed a blockade on Gaza in June 2007 when the militant group Hamas took control of the territory by force.
Since then, Israel has allowed in little more than basic humanitarian aid as a means of isolating Hamas and persuading militant groups to stop firing rockets into Israel.
The closure of Gaza's borders by the Israeli and Egyptian authorities has also meant that very few Gazans have been able to leave.
Before Free Gaza's boats set sail on Friday, the Israeli foreign ministry had said they wanted the activists to steer clear of the Gazan coastline, which it said was "the subject of an [Israeli Navy] advisory notice" that warns off foreign vessels from the "designated maritime zone".
But on Saturday, an Israeli spokesman said they would be allowed in.
"They wanted provocation at sea, but they won't get it," foreign ministry spokesman Aviv Shiron told the AFP news agency.
"We know who the passengers are and what they are bringing with them and so we have no problem letting them through."
The two vessels - named Liberty and Free Gaza - are carrying 200 hearing aids for children and 5,000 balloons.
"No matter what happens we have already achieved our goal by proving that ordinary citizens with ordinary means can mobilise a defence of human rights for Palestinians," organiser Paul Larudee told the AFP news agency.
"We want people to see the Palestinian problem as one of human rights, not feeding them rice," he added.
The activists on board the boats include Lauren Booth, sister-in-law of UK former Prime Minister Tony Blair, who is now an international Middle East peace envoy. Also on board is left-wing Greek MP Tasos Kourakis.
Israel withdrew its settlers from Gaza in 2005, but it still controls its coast, airspace and borders, and, until a ceasefire with Hamas was agreed in June, carried out regular military operations in the territory.
However, correspondents say the truce has not improved the situation for Gaza's population, except to reduce the number of Israeli incursions and the number of rockets fired by Palestinian militants.