Egyptian mediated talks between Hamas and Fatah in Cairo began on Thursday morning.
Earlier rounds of reconciliation efforts have failed, and the two sides remain bitterly divided nearly two years after Hamas overran Gaza.
In an effort to improve the negotiating climate, both sides announced on Wednesday that they would each release political prisoners from the opposing faction.
There was no information on how many detainees would be freed. On Tuesday, Fatah released 42 Hamas prisoners in the West Bank.