Officials in the Gaza Strip say Palestinian factions, after a day of violence, have reached an agreement to halt fighting and restore calm.
Fighting escalated in Gaza on Sunday following a call for new elections by the Palestinian president.
Late Sunday, gunmen kidnapped and killed a security officer, Adnan Rahmi loyal to the Fatah faction of President Mahmoud Abbas.
Earlier, suspected militants loyal to the governing Hamas group opened fire on pro-Fatah demonstrators in the northern Gaza Strip and fired mortars at the Gaza City office of the Palestinian president.
As fighting neared the President's office, Fatah gunmen seized control of two government ministries run by Hamas in what Prime Minister Ismail Haniyeh called an attempted coup.
A 19-year old woman was killed in the crossfire and many more civilians were wounded.
Hamas says a call for new elections by President Abbas is unconstitutional.
Fatah and Hamas have been locked in a power struggle ever since Hamas won legislative elections and took power in the Palestinian territories earlier this year.
Mr. Abbas said new elections are necessary after months of failed talks with Hamas, which currently controls the Parliament and government, but not the presidency.
A unity government is seen as a way of persuading international donors to restore aid to the Palestinians. They cut off funding after Hamas took power.
The United States, the European Union and Israel consider Hamas a terrorist group.