Police intervened as around a dozen young protesters sought to march towards the legislative building in Gaza City to stage a demonstration calling on the long-time political opponents to reopen reconciliation talks.
Witnesses told AFP that protesters holding signs reading "End the Division" were accosted by police as they marched past Gaza City`s Shifa hospital.
Several demonstrators were detained, and others fled the scene. The protest that had been planned outside the legislative building did not take place.
There was no immediate comment from Hamas.
It was the second time in a week that Hamas officials have detained members of a movement calling for a shake-up in the Palestinian political scene.
On Monday, police stopped about 20 young demonstrators from holding a sit-in in Gaza City`s Square of the Unknown Soldier.
One of the leading organisers of the unity movement in Gaza, Ahmed Arar, was arrested and released the following day. Hamas defended breaking up the protest, saying organisers had failed to seek a permit for the rally.
Thousands of young Palestinians have been joining groups on Facebook that call for an end to the split between Gaza`s Hamas rulers and the Fatah movement, which dominates the West Bank-based Palestinian Authority.
Taking inspiration from protest movements that have toppled dictators in the Arab world, they are using social networking tools and staging small protests in the West Bank and Gaza to try to build momentum for a unity government.
Organisers hope to stage their biggest rally yet on March 15, and are using Facebook and Twitter to call on Palestinians in the West Bank, Gaza and abroad to join demonstrations on that day. (*)