The hand of Israel is not being ruled out as Hamas announces an inquiry into an explosion that targeted the convoy of the West Bank-based Palestinian prime minister during a visit to the Gaza Strip.

Tuesday's blast injured several security guards of Rami Hamdallah but left him unharmed during a visit to the Hamas-run territory to open a public-works facility there.

The explosion happened shortly after Hamdallah's convoy passed through the Israeli-controlled Erez checkpoint, known to Palestinians as Beit Hanoun, in northern Gaza, an Al Jazeera correspondent at the scene reported.

Sources told Al Jazeera that Hamdallah and Ismail Haniya, senior political leader of Hamas, spoke by phone later in the day and agreed that Israel was behind the explosion because it appeared to be the incident's main beneficiary.

Youssef al-Mahmoud, a Palestinian Authority spokesperson, denied via the Palestinian news agency WAFA that any phone call took place between Hamdallah and Haniya.

Hamas has denied any involvement in the explosion, and said it would launch an investigation to "bring those behind the attack to justice".

Tawfiq Abu Naim, Hamas security chief, has been given the responsibility of heading the probe.

Reconciliation agreement

Hamas and Fatah, the two main Palestinian political parties, signed a reconciliation agreement in October 2017, ending a decade of division that saw two parallel governments operating in Gaza and the West Bank, respectively.

The agreement to form a unity government was signed in the Egyptian capital Cairo on October 13, but efforts to implement the deal have faced obstacles.

Hamdallah, who heads the Palestinian Authority government based in Ramallah, appeared on live television at the inauguration of a wastewater-treatment plant in Gaza.

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Shortly afterwards, he returned to Ramallah where he appeared unfazed as he delivered a brief address outside his office.

He said seven of his guards were wounded in the attack and they were being treated in hospitals across Ramallah.

"It [the attack] does not represent patriotism. It is a cowardly act that does not represent our people, nor does it represent the people of Gaza," Hamdallah said.

Majed Faraj, the Palestinian Authority intelligence chief, was part of the convoy that came under attack.

Fatah, the West Bank-based political party to which Palestinian President Mahmoud Abbas belongs, called the incident a "terrorist attack" and blamed it on Hamas.

"This attack is an attempt to kill all reconciliation efforts. It is a dangerous step aimed at spreading disorder and fighting among our people," Munir al-Jaghoub, who heads Fatah's information department at the Office of Mobilisation and Organisation, said.

"We demand that Hamas expedite its investigation. The developments have proven that Hamas has completely failed in providing security in Gaza, just as it has failed in providing a decent life for our people in the strip."

Sabotage alleged

On Hamas' part, Ahmed Bahar, the party's acting parliamentary speaker, said the explosion was a crime aimed at sabotaging reconciliation efforts, and called for the immediate launch of an investigation.

Speaking to Al Jazeera, Iyad al-Buzom, Gaza's interior ministry spokesman, said the act of placing blame "has a political dimension".

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"Here in Gaza, we take all the security precautions to welcome all the convoys and delegations and particularly the prime minister as he entered Gaza," he said.

"Several suspects were arrested a short while ago", and an investigation "to find out who was behind the explosion" is under way.

Mustafa Ibrahim, a Gaza-based political analyst, said there are "several sides who are benefiting from this explosion".

"We will hear Fatah saying that some members of Hamas do not want reconciliation, and likewise, we will hear Hamas saying this could have been a fabricated attack by Fatah's security services," Ibrahim told Al Jazeera.

"The ones who will pay the price are the Palestinian people themselves. The Palestinian Authority may impose more punitive measures against the Gaza Strip, and it is imperative that Hamas captures those behind the attack as soon as possible.

"This explosion will have repercussions for the people in Gaza."

Nickolay Mladenov, the UN's special coordinator for the Middle East peace process, condemned the attack and said in a Twitter post those behind it seek to "undermine" reconciliation.

Also commenting on the incident, Heather Nauert, US state department spokesperson, said on Twitter Gazans need "a real government that will provide basic services".

#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 @usaid @jdgreenblatt45 @USAmbIsrael #israel — Heather Nauert (@statedeptspox) March 13, 2018

Nauert's remarks came as the White House held a conference on the humanitarian crisis in Gaza, which has been under a land, sea, and naval blockade for more than a decade.

However, Palestinian officials were not expected to attend the conference.

Earlier this week the Palestinian Authority rejected the White House's invitation, saying the issue in Gaza was "political par excellence".