Palestinians are staying indoors to avoid the violence on the streets of Gaza. Four Gazans describe what is happening on their doorstep.
MUHAMMAD ABUSHABAN, 21, STUDENT, GAZA CITY
Armed men are on top of the building opposite our house, they are shooting at the al-Saraia military building about 500 metres away from us.
They have been shooting since this morning. Hamas wanted to shoot the armed men inside to make them surrender. They refused, so a terrible amount of gunfire began.
We are listening to the radio and watching TV; both sides are claiming things against the other side.
The streets are completely empty apart from the gunmen.
We have no chance to leave our house, even though this is the second day of my final year university exams.
I have never left Gaza. It's difficult [sound of gunfire], both sides have their military buildings in between civilian houses in the city. The way both sides are shooting [sound of gunfire] is completely wild.
AHMED, 27, BEIT LAHIYA, NORTHERN GAZA
I was studying abroad for two years until I came back last week. People are not the same any more, they look sad and hopeless.
To be honest, here in the north things are calm. It's now a green bloc, all under Hamas control.
Last night a Fatah leader was assassinated in Jabaliya refugee camp. The battle lasted four or five hours, it was a couple of blocks away and we could hear the bullets flying.
So people are thinking: "That's it. He was the last one."
People are blaming the Fatah guy for staying - it was obvious Hamas were targeting the Fatah leadership in the northern areas even though the man himself had good relations with everyone.
I don't think this is a civil war because I don't see civilians involved. I think it's a war between fanatics on both sides.
People don't understand the Palestinian Authority - they are all paralysed and there's no leadership. They can't even protect their own leaders.
FATHI, 50, PALESTINIAN AUTHORITY EMPLOYEE, GAZA CITY
I'm not far away from the house of the main Fatah spokesman, Hamas are attacking his house. It started late last night.
I am a member of Fatah. I am not satisfied with the Fatah leadership. Until now they have been calling for calm, but when vicious aggression is going on, you need to fight it.
So many times they have agreed on a ceasefire and Hamas have used it to act on the ground.
The situation is horrible. The picture the media is putting across is that both sides are attacking the other. That's wrong - Hamas are attacking the legitimate security forces.
HAKEEM, 40, TEACHER, AL-MAGHAZI CAMP, CENTRAL GAZA
I'm listening to the news on TV and radio to hear what both sides are saying.
I heard that Hamas has declared central Gaza a military zone. To be frank, I don't know what that means.
Presumably it's directed at the Palestinian Authority. Both sides have their own forces now.
Hamas has taken over the checkpoint two kilometres from the refugee camp where I live. They're trying to take over the area.
The situation is miserable, bad and disappointing.