Palestinian Interior Minister Hani al-Qawasmi resigned on Monday, rocking a two-month-old unity government, after the biggest surge in factional fighting in months revived fears of civil war.
Hani al-Qawasmi, picked by the rival Hamas and Fatah factions as a compromise candidate for the interior post, whose responsibilities include overseeing the security services, first tendered his resignation last month but had agreed to stay on.
Earlier, two Palestinian gunmen were killed in Gaza in fighting between the rival Hamas and Fatah groups, despite an Egyptian-mediated truce aimed at ending the deadliest outbreak of factional violence in months.
As interior minister, Qawasmi was to have overseen Palestinian security services but officials said the former academic faced competition from powerful Fatah rivals for control of the armed contingents.
The resignation cast new doubt on whether the power-sharing partnership between Islamist Hamas and secular Fatah could continue.
Sources in President Mahmoud Abbas's Fatah said tensions were so great with Hamas, its power-sharing partner, that their unity government could collapse within days if the bloodshed did not stop.
"A new interior minister will be agreed upon soon in consultations and agreement with President Mahmoud Abbas," a senior government official said.
Filling the post had been one of the main obstacles to forming the current coalition government.
'Zionist group responsible for escalation'
In the latest violence, dozens of Hamas gunmen exchanged fire with Fatah security officers and bodyguards of Maher Meqdad, a Fatah spokesman, in Gaza City.
Hospital officials said two of the security officers were killed and 10 people were wounded.
Hamas's armed wing said its men had rushed to the scene after Fatah gunmen opened fire from rooftops at homes belonging to its members. Fatah said Hamas gunmen torched an office belonging to the group at the scene of the clashes.
Hospital officials said a civilian, shot in factional fighting on Sunday, died of his wounds, raising to seven the number of people killed since a new round of clashes erupted over the weekend. At least 40 people have been wounded.
Fatah officials accused Hamas of violating the ceasefire agreement signed between the rival factions on Sunday night. According to the officials, a radical group inside Hamas was attempting to destroy the understandings and the truce.
Hamas officials, on the other hand, said that the "Zionist group" inside Fatah was responsible for the recent escalation.
Under the ceasefire brokered by Egyptian mediators and announced by Hamas and Fatah leaders in Gaza on Sunday, both sides were to have pulled gunmen off the streets and swapped about 20 hostages.
Palestinians had hoped the recent deployment of Palestinian police in Gaza under a new security plan would curb growing lawlessness and ease tensions between the long-time rival factions.
Previous police deployments in Gaza have not fully secured the territory, which has sunk further into poverty and political disarray since Israel withdrew troops and settlers in 2005.