Gaza.

Farooq Burney gives his testimony in the link above.

The activists appear to be corroborating each other.  

The strong emerging narrative from activists aboard the Mavi Marmara is that some time near the end of the early morning (fajr) prayer (at approximately 4:10), Israeli forces attacked and threw and/or dropped stun grenades and/or tear gas onto the Mavi Marmara from boats alongside and/or helicopters above.  Israeli forces were apparently also using rubber bullets from the start.

A first helicopter dropped soldiers onto the deck who were overcome and disarmed, one clearly thrown on the deck below the top deck, and one or more (possibly 3) was locked in a room. Once the Israelis had realised that it was not going exactly to plan, and that some of their number were effectively captive, they turned to live ammunition.

It is clear from the limited Israeli footage we have that this is at least true in part.

There is the possibility of another helicopter attempting to drop more soldiers - there was definitely more than one Israeli helicopter at the scene as one was videoing from above whilst a second was dropping soldiers onto the top deck - and there is general agreement that soldiers were shooting indiscriminately from a helicopter.