JERUSALEM, Aug. 26 (Xinhua) -- An Israeli who sailed to the Gaza Strip with other international activists in defiance of an Israel-imposed sea blockade was arrested, a spokeswoman for the protest organizer said Tuesday.

    Professor Jeff Halper, a Jerusalem resident, was interrogated at a border crossing on Tuesday afternoon on his way back from the Palestinian enclave, before police put him into custody at a police station in the southern down of Sderot, Angela Godfrey-Goldstein, a contact person for Free Gaza Movement, told Xinhua.

    She said that Halper, the only Israeli participant in the voyage, was arrested for violating the law prohibiting Jewish citizens from entering the coast strip.

    Local news service Ynet quoted police spokesman Micky Rosenfeldas saying that Halper was taken to a police station in the south Tuesday, without elaborating.

    The arrest came two days after Halper and some 40 other activists with the U.S.-based group reached the Gazan coast in a mission they said aimed to break the siege the Jewish state has imposed upon the Hamas-ruled area.

    Before giving the so-called "one-time" green light for the two boats, Israeli government had warned that such a provocative move "constitutes the legitimization of a terrorist organization" and that all options would be considered.

    Israel tightened its restrictions on the Palestinian region since Hamas, a group Israel blacklists as a terrorist organization, seized control of the area last year from the long-dominant Fatah faction. The land border, sea and air of the strip are currently all under Israeli control.