first of all, TWO SIDES of the story.
I guess you all will agree, as a normal security procedure, every country has rights to know what is imported into its territory. And I guess, the volonteers were impeding inspection of premises,
"..such as physically blocking the steering room, or blocking the engine room downstairs... But that was just symbolic resistance." (BBC: http://news.bbc.co.uk/2/hi/middle_east/10195838.stm)
...and the fight ensued...
Another note,
"Israel says it allows about 15,000 tonnes of humanitarian aid into Gaza every week.
But the United Nations says this is less than a quarter of what is needed."

Little calculation... Population of Gaza strip is about 1,4 – 1,5 MLN people. Now, 15,000,000KG is delivered to Gaza weekly. It means that every person in Gaza, including just-born babies and elder people receive over 10KG of humanitarian aid weekly.
I guess, this aid mostly includes food and medicaments.
Now, I am wondering, does each of us really consume even 10KG of food and medicaments every week?
And United Nations says this is "less than a quarter of what is needed"?? it means as per on United Nations each person, including babies needs 40KG (!) of goods every week??
wow..