Palestinian President Yasser Arafat has declared a state of emergency and approved a scaled-down cabinet to deal with it.
Mr Arafat is facing Israeli threats to "remove" him after further Palestinian suicide bombings.
Palestinian officials said Arafat's decree aimed to reinstate security in Palestinian areas, where militant factions opposed to peacemaking with Israel have grown powerful three years into a revolt for statehood.
But Palestinian security services have been impaired by Israeli offensives and blockades that have bred resentment and fueled the popularity of militants, raising questions whether any "emergency" crackdown might quickly fizzle.
"The declaration of emergency is meant to bolster the principle of one Palestinian Authority and maintain the rule of law, because our situation is very, very critical," said a senior Palestinian official.
A Palestinian Islamic Jihad militant killed 19 people in a suicide bombing in Israel on Saturday, a day before the onset of the Jewish Yom Kippur holiday. Mr Arafat condemned the attack.
Israel responded by bombing what it called a Palestinian militant training camp in Syria and said the possibility of carrying out its decision in principle to expel Arafat might depend on Palestinian actions in the coming 48 hours.
Israel claims Mr Arafat has incited militant violence throughout the revolt, a charge he denies, and says a US-backed "road map" peace plan envisaging a Palestinian state will go nowhere as long as he stays in power.