Several dozen police marched in Gaza City, firing into the air before storming into the parliamentary compound. The reason -- they say they don't want the Interior Ministry, which controls security forces, to be taken over by Hamas.
In Ramallah in the West Bank, there was another protest. Fatah activists climbed onto the roof of the parliament building there, demanding their leaders' resignations.
Both actions were soon over, and no casualties were reported.
But they were just the latest sign of growing tension in Palestinian society following parliamentary elections last week.
The 25 January elections ended decades of Fatah domination and produced a crushing victory for Hamas, the militant group that has called for the destruction of Israel.
That led to international calls for the Islamic militant group to disarm and renounce violence -- or face cuts in aid.
The latest such warning came on 27 January from the United States, which has earmarked $234 million in aid for the Palestinians this year.
"If there is a Hamas government, which now appears likely, we're going to have to review all aspects of our aid program, based on our policy and our law," White House spokesman Sean McCormack said on 27 January. "So standing here right now, I can't give you the full implications of that. There will have to be a review of all those aspects of our aid program."
Officials from the EU --the biggest donor to the Palestinian Authority -- have also indicated that relations could suffer if Hamas refuses to renounce violence.
Hamas' response has been one of defiance.
In Damascus, the group's political leader, Khalid Mish'al, said Palestinians had a right to financial support because they were, as he put it, languishing under occupation. And he urged the European Union not to punish the Palestinian people by cutting aid.
In Gaza City, another Hamas leader, Ismail Haniyah, called the aid warnings an attempt at blackmail. And he said the Palestinians would only end their armed struggle when Israel ended its occupation.
"This [foreign] aid can not be a sword over the heads of the Palestinian people, and will not be material to blackmail our people, to blackmail Hamas and the resistance," Haniyah said. "It is rejected."
Now correspondents say both Hamas and the international community face dilemmas.
The United States and European countries say they won't deal with a government run by a terrorist organization. But a sharp cutoff in aid could further increase tensions in the region.
And if Hamas does not renounce violence, the group would face a drop in much-needed aid, and Palestinian aspirations for an independent state could receive a major setback.