A senior Cairo-based Hamas official crossed Monday from Egypt into the Gaza Strip ahead of a new attempt to reconcile the militant Islamist movement and its Palestine Liberation Organisation rivals.
Mussa Abu Marzuq, head of external affairs in the movement's political office, was seen entering the Hamas-ruled coastal strip through the Rafah frontier crossing.
A delegation of the Palestine Liberation Organisation, which is headed by Palestinian president Mahmud Abbas and dominated by his Fatah movement, is to go to Gaza from the West Bank on Tuesday for talks with Hamas, members said.
Independent Palestinian MP Mustafa Barghuti told AFP that his fellow delegates were Fatah's Azzam al-Ahmad, Bassam al-Salhi of the socialist Palestine People's Party, businessman Munib al-Masri and Arab Palestinian Front leader Jamil Shehadeh.
Barghuti said the sides would discuss "forming a national consensus government and holding elections," among other issues.
Hamas's Gaza interior ministry said 10 Fatah members imprisoned for "breaches of public order" were freed on Monday "as a goodwill gesture to support national reconciliation efforts".
Immediately upon his arrival, Abu Marzuq met with Gaza prime minister Ismail Haniya, the premier's office said.
Longtime tensions between Hamas and Fatah boiled over in a week of fighting in 2007 that left the Islamist movement in control of Gaza and effectively divided the Palestinian territories in two.
The two sides have made repeated attempts to heal the rift, including an Egyptian-brokered deal in 2011 in which they agreed to make way for an interim government of independents to organise fresh elections throughout the territories.
The agreement has never been implemented.
Hamas's fortunes have slipped since July 2013 when the Egyptian army deposed the movement's ally, president Mohamed Morsi of the Muslim Brotherhood, although Abu Marzuq is still based in Cairo.
The Hamas leadership in exile left its Damascus headquarters last year, with its political chief Khaled Meshaal moving to Qatar.
Meshaal narrowly survived a 1997 Israeli assassination bid when Mossad agents injected him with poison on a street in Amman but were captured by Jordanian authorities.
He fell into a coma and a furious King Hussein demanded Israel hand over the antidote if it wanted the captured agents to be freed.
Meshaal himself rose to the top of Hamas after the Israeli assassination of its spiritual leader and co-founder Sheikh Ahmed Yassin in Gaza in March 2004, and the killing of his immediate successor Abdel Aziz Rantissi a month later.
Israeli officials have repeatedly warned that none of Hamas's leaders, including Haniya in Gaza, are immune from potential attack.