A bomb blast targeted Palestinian prime minister Rami Hamdallah's convoy during a rare visit to the Gaza Strip on Tuesday, leaving him unhurt but provoking outrage over what officials called an assassination attempt.
The attack is likely to further increase tensions between Hamas -- which denied any involvement -- and president Mahmud Abbas's Fatah, with a reconciliation agreement between the two all but dead.
Palestinian intelligence chief Majid Faraj was also in the convoy but was not injured in the explosion, which occurred shortly after they entered the territory.
At least six people were wounded, with none of their injuries believed to be life-threatening.
A security source in Gaza said the convoy was also fired on by unknown gunmen at the time of the explosion, before Hamas security forces sealed off the area.
After the attack, Hamdallah briefly appeared at the opening of a wastewater treatment facility in Gaza before cutting short his visit and returning to the Israeli-occupied West Bank, where his government is based.
"It was a very well-planned attempt. It was a roadside bomb about two metres into the ground," Hamdallah said at his office upon his return.
A statement on official Palestinian media said Abbas considered it a "cowardly targeting" of Hamdallah's convoy and held Hamas responsible.
There was no immediate claim of responsibility.
Radical Islamists opposed to Hamas also operate within the Gaza Strip and have regularly been behind unrest.
The Hamas interior ministry said they had arrested three suspects and begun an investigation.
- 'Same hands' -
A statement from Hamas condemned the attack, saying it was done by the "same hands" responsible for the assassination of one senior Hamas figure, Mazen Faqha, and the attempted assassination of another last year.
Hamas blamed the killing of Faqha on Israel. The second attack, an explosion targeting Hamas's head of security in Gaza, is widely believed to have been the work of radical Islamists.
Hamas criticised Abbas's accusation, saying it "achieved the goals of the criminals."
Another senior official, Tawfiq Abu Naim, said "whoever who did this only serves the (Israeli) occupation and is doing what the occupation demands."
The explosion came a few hundred metres (yards) after Hamdallah's convoy crossed through the Palestinian Authority-run checkpoint into Hamas-controlled territory.
Two cars with blown-out windows were being removed from the scene of the explosion shortly afterwards, an AFP correspondent reported.
The visit came as reconciliation efforts between Hamas and Abbas's Fatah party have faltered.
Hamas seized Gaza from the Fatah-dominated Palestinian Authority (PA) in a 2007 near civil war and multiple attempts at reconciliation have since failed.
Hamas and Fatah signed a deal in October that was supposed to see the Islamists hand back power in Gaza, but it has all but collapsed.
While Hamas did hand over control of Gaza's borders to the PA, it maintains full control of the rest of Gaza, with its police force and armed wing still operating throughout the territory.
The future of that armed wing, which has fought three wars with Israel since 2008, has proved one of the largest sticking points in implementing the reconciliation agreement.
- 'Risks exploding' -
Hamdallah's government is recognised by the international community, while Hamas is blacklisted as a terrorist organisation by the European Union and the United States.
The prime minister called for Hamas to allow his government to take control in Gaza.
"We are talking about internal security -- the police and the civil defence," he said. "Without security there won't be a government."
The UN envoy to the Middle East peace process, Nickolay Mladenov, condemned the attack and said "Hamas has the responsibility to ensure that the government is able to carry out its work in the strip without fear of intimidation, harassment and violence."
Mladenov has warned of the consequences of the desperate humanitarian suffering in the strip, saying in January that Gaza "risks exploding in our face again."
The White House is due to hold a conference on the deteriorating humanitarian situation in Gaza on Tuesday, but no Palestinian officials are expected to attend despite an invitation.
The Palestinians were enraged by President Donald Trump's decision to break with longstanding US policy by recognising Jerusalem as Israel's capital and have refused to meet with his peace envoys since.
Israel has maintained a blockade of Gaza since 2007, which it says is necessary to isolate Hamas, while Egypt has also kept its border with the enclave largely closed.
US State Department spokeswoman Heather Nauert said on Twitter that "Palestinians in Gaza need a real government that will provide basic services -- not today's attack on PA officials trying to inaugurate a water treatment plant desperately needed in Gaza."