An Austrian pro-Palestinian activist deported from Israel has complained of ill treatment at the hands of aggressive Israeli forces.

Julia Hurnaus, 25, was one of about 40 so-called "flytilla" activists expelled on Tuesday from Israel, where they had flown for a protest action over the weekend.

"People were injured, people were hit in the face for no reason," Hurnaus told the Austria Press Agency upon her return to Vienna late Tuesday.

"It was all so aggressive, we were treated badly," she added.

The activists were constantly shouted at and any communication with the outside world was blocked during their detention.

Arrested as they flew into Israel as part of the "Welcome to Palestine" campaign to visit the Palestinian territories and Palestinian families, the activists were taken to a detention centre in an airless bus by high temperatures and with no water during the three-hour drive, Hurnaus said.

Some with health problems were refused treatment, she also claimed, insisting the protest was a peaceful one and was never meant as a provocation to the Israeli authorities.

"The point was to travel to Palestine because we have the right to" and to visit people there, she said.

Hundreds of people from Europe and the United States were prevented from flying to Israel or denied entry and taken into custody over the weekend as they sought to join the "Welcome to Palestine" campaign.

The timing of the action, just as a flotilla of ships trying to break a blockade on the Gaza Strip was prevented from leaving Greece, led some to dub it a "flytilla," although organisers denied their mission was linked to the attempt to run the blockade.