http://news.bbc.co.uk/2/hi/middle_east/6744713.stm
Militants of the Palestinian group Hamas have begun to attack positions of rival faction Fatah in Gaza as levels of violence reach a new intensity.
Hundreds of Hamas fighters began moving in on Fatah posts after giving their rivals two hours to leave.
Fatah says it will meet later to decide whether to leave its unity government with Hamas. President Mahmoud Abbas has called for an immediate truce.
Some 16 people have been killed on the streets of Gaza in the past 24 hours.
The residences of both Mr Abbas, Fatah's leader, and of Prime Minister Ismail Haniya, of Hamas, have been targeted with gun and shell fire.
Witnesses said it was the worst fighting they had experienced in Gaza during 18 months of internal strife.
"Since early morning we have heard explosions and shooting. We can't go and buy any food, we can't stand in front of the windows, all our children are in one bedroom," said Gaza City resident Adnan.
Ransacked
A statement issued from Hamas-operated mosques had given Fatah fighters, described as "Zionist collaborators" until 1100 GMT to evacuate Gaza positions.
They have killed all hope. They have killed the future
Lt Col Burhan Hamad,
Egyptian mediator
Hamas-run radio stations then said the group's fighters had taken control of several security positions in northern and central Gaza, and in Khan Younis in the south.
Some reports said 200 Hamas fighters had surrounded about 500 Fatah rivals at the headquarters of the Fatah-allied security forces in Gaza City.
Fatah spokesman Abdel-Hakim Awad said: "The security forces... will defend the security headquarters with all their might."
Former Palestinian Foreign Minister Nabil Shaath told Associated Press news agency that Hamas militants had ransacked his home in Beit Lahiya.
In the West Bank, forces loyal to Fatah stormed the Hamas-controlled al-Aqsa television channel.
A cousin of Abdel Aziz Rantissi, a Hamas leader who was killed by Israeli forces in 2004, was reportedly kidnapped and killed by Fatah gunmen.
In a statement Mr Abbas accused some Hamas figures of "planning a coup against the legitimate [Palestinian] institutions".
Factional fighting in Gaza City 12 06
Few places are considered safe in the strife-torn streets of Gaza City
A spokesman for Fatah said it would meet at 2000 (1700 GMT) to decide whether to stay in the unity government it formed with Hamas in March.
The government was intended to halt the factional fighting and ease Western sanctions.
Mr Abbas called on Tuesday for an immediate ceasefire and for "talks to end all violence and in-fighting".
However, there have been a number of ceasefires and all have been short-lived.
'No interest in talks'
The BBC's Tim Franks, in Jerusalem, says that inside Gaza most people are now staying indoors listening to the violence rage outside.
The fighting has been intense and brutal with few places considered to be safe and with hospitals becoming battlegrounds, he says.
In one incident, a senior member of the al-Aqsa Martyrs' Brigades, linked to Fatah, was shot 41 times while in a hospital bed in the town of Beit Hanoun.
The International Committee of the Red Cross said it was "deeply disturbed by the events in Gaza over the last two days, particularly the attacks in and around two hospitals in the northern part of the Gaza Strip".
Frustrated Egyptian mediators said the rival factions appeared uninterested in talks.
The head of the mediation team, Lt Col Burhan Hamad, said: "It seems they don't want to come. We must make them ashamed of themselves. They have killed all hope. They have killed the future."
