Palestinian protesters threw shoes and chairs at the convoy of United Nations Secretary-General Ban Ki-moon as it entered the Gaza Strip on Thursday, witnesses at the scene told dpa.
Several dozen family members of Palestinian prisoners waited for Ban on the Palestinian side of the Erez crossing with Israel, north of Gaza City.
When his convoy of several UN cars crossed over, it was hit by objects thrown at it, the witnesses said. It was not clear whether the vehicle transporting Ban was hit as well, they said.
The protesters were angry at what they regard as a failure by world leaders to act on behalf of their relatives jailed in Israel.
Some 4,000 Palestinian "security prisoners" are held in Israel.
Hamas police cars and jeeps accompanied the UN convoy.
Ban was heading to the southern Gaza Strip town of Khan Younis, where he is to inaugurate a UN-sponsored construction project.