Palestinian Prime Minister Rami Hamdallah has cut short a rare visit to Gaza after an explosion targeted his convoy.
Mr Hamdallah, who was not hurt, left the Hamas-run territory through the Erez crossing shortly after opening a wastewater treatment facility.
The explosion had gone off near his convoy shortly after he arrived in Gaza and lightly injured seven people.
He had been expected to hold a number of other engagements in the territory.
Palestinian intelligence chief Majid Faraj was also part of the convoy but was not hurt either, a security source said.
A statement on official Palestinian media said President Mahmoud Abbas considered it a "cowardly targeting" of Mr Hamdallah's convoy and held his rivals Hamas responsible.
There was no immediate claim of responsibility.
Radical Islamists opposed to Hamas also operate within Gaza and have regularly been behind unrest there.
The Hamas interior ministry confirmed there had been an explosion and said security forces were investigating the incident.
The two major Palestinian factions signed a reconciliation agreement in October that was supposed to see Hamas hand over power, but it has all but collapsed.