Hamas police on Monday detained at least six protesters at a Gaza City demonstration calling for unity between the Islamist group and its bitter West Bank rival Fatah.
The arrests came a day after Hamas police held five demonstrators from the unity movement as they marched past Gaza City's Shifa hospital on their way to rally in front of the legislative building.
A media coordinator for the unity movement in Gaza told AFP that the six people held on Monday were detained at a small protest outside the International Committee of the Red Cross headquarters in Gaza City.
A separate bigger protest of several hundred people was held outside the Al-Azhar University, but demonstrators scattered as soon as police showed up, witnesses told AFP.
Protesters waved Palestinian flags and banners reading "End Division" and called on passersby to join large demonstrations planned for March 15.
There was no immediate comment from Hamas on the detentions.
Last Monday, Hamas security forces also intervened to prevent members of the unity movement from staging a sit-in at Gaza City's Square of the Unknown Soldier, arresting one of the movement's organisers.
Hamas defended breaking up the protest, saying protesters did not have 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.
The two groups are long-time rivals whose animosity boiled over in the summer of 2007 when bloody clashes broke out between the groups in Gaza, which saw Hamas oust Fatah from the coastal enclave altogether, a year after Hamas won legislative elections.
Successive rounds of reconciliation talks between the groups have failed to produce a unity agreement, and have led to deep frustration among many Palestinians at the continuing division.
Taking inspiration from protest movements that have toppled dictators in the Arab world, some young Palestinians are now 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.