Unidentified gunmen opened fire on security vehicles escorting Palestinian Prime Minister Ismail Haniyeh's convoy through Gaza today.
The Hamas leader was unhurt, however, and officials in Mr Haniyeh's office said the attack did not appear to be an assassination attempt.
But it comes at a time of growing tensions between rival Palestinian factions that have sparked fears of civil war.
Officials said gunfire hit vehicles of a Hamas-led police force that was behind cars carrying Mr Haniyeh, who had just finished a speech at a mosque.
One of the vehicles was torched. Hamas security officials returned fire, officials said.
During his speech, Mr Haniyeh said he would reject any moves by President Mahmoud Abbas to oust his government.
Mr Abbas has hinted he might fire the Hamas government after efforts to form a unity cabinet foundered over the Islamist movement's refusal to soften its stance toward Israel.