Gaza bomb attack after judge killed
Haniya, left, was due to be travelling for a month
At least one person has been injured in a grenade attack on a rally of the ruling Hamas party.
The attack comes after Ismail Haniya, the Palestinian prime minister, cut short a foreign tour.
He was due to be travelling for a month but violence in the Palestinian territories between supporters of Hamas and Fatah has forced his early return.
The grenade was thrown at a rally in the Nusseirat refugee camp which was being held in protest at the killing of an Islamic tribunal judge who was shot dead in the southern Gaza town of Khan Yunis earlier Wednesday.
Hamas has blamed a Fatah "death squad" for the killing of Bassam al-Farah.
"If Hamas and Fatah would swallow their pride and work together, Palestinians might in fact have their own state."
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Al-Farah was a prominent member of the Hamas movement.
Witnesses said four gunmen grabbed al-Fara as he emerged from a taxi outside a courthouse.
Three of them forced him onto his knees while the fourth pulled out a weapon and shot him, they said.
Mushir al-Masri, a Hamas member of parliament, said: "The seekers of the coup in Fatah bear the responsibility for all actions of chaos taking place in the Palestinian streets."
Tawfik Abu Khoussa, a Fatah spokesman, rejected the accusations.
"We condemn all acts of anarchy whatever may be behind them, we call on the brothers in Hamas to stop firing accusations before the investigation," he said.
Speaking to reporters in the Sudanese capital, Khartoum, on Wednesday, Haniya dismissed fears that the violence could develop into a civil war.
"We want to assure you that words such as 'civil war' don't exist in our dictionary. They don't exist in our make-up, in our culture," he said.
"We don't have time for internal feuds. We will protect the national unity of the Palestinian people and we will thwart any attempt to instigate an inter-Palestinian struggle."
However, one sign of the growing uncertainty and deteriorating security situation was the demonstration outside the parliament building in Gaza.
Protesters are calling for national unity
Hundreds of protesters had earlier gathered in the square to protest at the killing of three young children of a Fatah-allied Palestinian intelligence officer two days ago.
Nour Odeh, Al Jazeera's correspondent in Gaza, said the crowd comprised schoolchildren, mothers, civil society activists and former members of the Palestinian Legislative Council.
The crowd marched into the PLC where speeches were made to current members, all saying the only way to achieve national security was through national unity.
Hamas and Fatah have adopted entrenched positions of late. The Fatah-led PLO executive committee has recommended calling early elections.
"If I am forced to stop an outlaw I will do it again and I will not regret it"
Commander, Executive Force
These calls have been rejected by Hamas, which says the executive committee does not have the authority to make such recommendations.
Meanwhile on the ground, the cycle of killing continues. Al Jazeera's David Chater joined a patrol of the Hames-led Executive Force in Khan Younis.
The group has had its numbers thinned by targeted killings by Israel, but with more than 5,000 men they are a force to be reckoned with.
Its commander is on that country's wanted list and he told Al Jazeera that his group's mission is to protect the Palestinian people from chaos.
He has already been in a shooting match with rival Palestinian factions and, although he says he hopes he is not in that situation again, he said that if he is "forced to stop an outlaw, I will do it again and I won't regret it".