The Gaza Strip has seen more clashes a day after Palestinian leader Mahmoud Abbas called for early elections to end an economic and security crisis.
Ismail Haniya rejected the election call as unconstitutional
Mortars were fired at Mr Abbas's office in Gaza City, and a 19-year-old woman was killed as rival Fatah and Hamas supporters clashed in the streets.
A Hamas minister's convoy was attacked, as was a presidential guard base.
Prime Minister Ismail Haniya, who heads a Hamas-led government, has said new elections could incite further unrest.
"The Palestinian government rejects the call for holding early parliamentary elections because it is not constitutional and may lead to a large disturbance in the Palestinian territory," said Mr Haniya.
Sunday's violence began with a pre-dawn raid by masked gunmen on a training camp for Mr Abbas' presidential guard left one guard dead. Hamas denied any involvement.
Hours later, Foreign Minister Mahmoud Zahar of Hamas escaped injury when gunmen opened fire on his convoy.
He blamed the attack on Fatah and accused Mr Abbas of attempting to stage a coup.
"What's happening is a real military coup. Assassinations and attempted assassinations, the occupation of headquarters and ministries - it will be met with all harsh measures that are legal."
That incident provoked a fierce gun battle on the main streets of Gaza during which Hamas gunmen fired on Mr Abbas's empty Gaza residence. There was also shooting outside some government ministries.
In the evening gunshots were fired into the crowd at a pro-Fatah rally in the north of Gaza.
There were several reports of injuries throughout the day, including civilians and a French journalist.
Mr Abbas on Sunday met Palestinian election officials, who said they needed at least three months to prepare for new presidential and parliamentary polls.
"We explained to him the phases of holding elections, and how much time it would take for holding such elections, which is at least three months, including challenges," the head of the Central Election Commission, Hanna Nasser, said.
In a major policy speech in Ramallah on Saturday, Mr Abbas blamed Hamas for the crisis, saying the Palestinian people were suffering from an economic siege that had halved incomes.
In January, Hamas trounced the long-dominant Fatah at the polls.
But the election of a group which refuses to recognise Israel and renounce violence triggered the suspension of Western aid to the Palestinians.
Sunday's violence started with a pre-dawn raid
For months, the two sides have tried and failed to agree on a national unity government to find a way out of the crisis but as the politics have faltered, tensions have risen, provoking fears of civil war.
The election call appears to have deepened the already great rivalry between Hamas and Fatah, says the BBC's Nick Thorpe in Jerusalem.
Many Palestinians say the president has no right to dissolve the government, which was elected in January and is due to remain in office until 2010.
But internationally, Mr Abbas's call was widely welcomed. The US administration expressed the hope that fresh elections could help end violence in the region.
Mr Abbas' call was welcomed by outside powers
Meanwhile, UK Prime Minister Tony Blair - who is touring the Middle East - urged the international community to back Mr Abbas's effort to break the deadlock.
Israel said Mr Abbas had its support in his attempt to bring peace to the Palestinian territories.