I think civil war is not too strong a term for what is going on now:
From the Jerusalem Post:
At least 25 Palestinians were killed and 80 were wounded as Hamas fighters overran two of Fatah's most important security installations in the Gaza Strip on Thursday. Witnesses said the victors dragged vanquished gunmen from the building and shot them to death gangland-style in the street in front of their families.
The headquarters of the General Security Service, commanded by Ramallah-based General Tawfik Tirawi, fell to Hamas gunmen. Hamas said documents it found there prove that the Fatah-affiliated security apparatus has close ties with the Central Intelligence Agency (CIA). Hamas said it would show the documents on television in the coming hours.
Elsewhere, the capture of the Preventive Security headquarters was a major step forward in Hamas's attempts to complete its takeover of all of Gaza. Hamas followed up that victory by demanding Fatah surrender another key security installation.
And from IHT:
Thursday's assaults on Fatah put Hamas close to full control of Gaza. Only the presidential compound of Abbas and the Suraya headquarters of the National Security Forces, the Palestinian army, remained under Fatah's control. But Hamas had surrounded Al Suraya, calling on the occupants to surrender, and the compound was under attack Thursday.
Abbas came under pressure from within Fatah and from some of his other allies to suspend participation in the so-called unity government with Hamas, which began in March, and to declare a state of emergency.