The Hamas police arrested two people on Tuesday and prevented a group of youths from holding a conference sponsored by the Palestine Liberation Organization (PLO) , witnesses said, Xinhua reported.
The conference was aimed at supporting a national agreement that Egypt brokered between Hamas and President Mahmoud Abbas' Fatah party.
Dozens of policemen surrounded the hall where the conference was scheduled to be held, prevented people from entering, "beat several organizers and arrested two of them," said Ibrahim Al- Shatali, one of the organizers.
Hamas told the organizers that PLO's activities are banned, Al- Shatali said.
There has been no comment from the Hamas, which has been controlling Gaza since routing pro-Abbas forces and ousting the Fatah party in 2007.
The agreement between Hamas and Fatah prepares to end the political division between Gaza and the Fatah-ruled West Bank. The two sides are now talking to form a technocratic government that would prepare for holding elections after a year of its formation.