GAZA CITY, Gaza Strip ? The Palestinian standoff intensified Sunday after Hamas rejected an ultimatum from President Mahmoud Abbas to endorse a plan implicitly recognizing Israel, and a pregnant woman was killed during a clash between the rivals’ forces in Gaza.

Abbas will order a referendum on a plan drawn up by top Palestinian prisoners in an Israeli jail calling for a Palestinian state in the West Bank, Gaza Strip and east Jerusalem alongside Israel, a Fatah official said Sunday. Abbas set a Tuesday deadline for Hamas agreement.

An Abbas-Hamas struggle over control of security forces has ignited several violent incidents. Hamas formed its own militia last month, and on Saturday, a similar Fatah force took to the streets in the West Bank town of Jenin. On Sunday, Fatah militants said they have a force of 1,250 gunmen ready to deploy in Gaza as well.