Ismail Haniyeh, prime minister of the Islamist movement's government in the coastal enclave, said other armed groups in the Gaza Strip should observe what has amounted to a ceasefire since Israel's major offensive a year ago. That, Haniyeh said, was in the interests of protecting Gazans from Israeli attacks.

Monday, Israel's defense minister had warned Hamas to rein in its allies "or else" -- a threat of more Israeli action.

Rocket fire by smaller groups Islamic Jihad and the Popular Resistance Committees, and Israeli air strikes that killed several Palestinians, made the past two weeks among the most violent since the three-week war that killed 13 Israelis and over 1,400 Palestinians before a ceasefire in mid-January 2009.

"We call upon Palestinian factions to intensify their meetings in order to reinforce the national agreement and to work in a joint spirit to protect our people and to protect our interests and to block any possible Israeli aggression against our people," Haniyeh said before a cabinet meeting in Gaza.

Despite denials from some of the smaller groups, Hamas has insisted lately there was an agreement to hold back on attacks.

EGYPTIAN RELATIONS

While hostility between Hamas and Israel is the norm, the Palestinian Islamist movement has also been concerned of late over a deterioration in relations with Egypt, which controls the short southern border of the Gaza Strip.

Already frustrated in its efforts to promote reconciliation between Hamas and the rival Fatah party of West Bank-based Palestinian President Mahmoud Abbas and by its difficulties in brokering a prisoner swap between Hamas and Israel, Cairo was angered last week by the death of a soldier at the Gaza border.

He was shot during clashes when Hamas supporters rallied at the frontier in the town of Rafah to protest at Egyptian efforts to stem supplies reaching Gaza through secret tunnels.

Egyptian officials have said the soldier was hit by a bullet fired from the Palestinian side. Hamas spokesman Sami Abu Zuhri said Tuesday there was evidence the Egyptian border guard could have been hit by a bullet from his own side.

Whatever the case, Haniyeh said, Hamas was working in good faith to clarify what happened and to protect relations with Cairo: "We are carrying out an investigation ... (which) aims to arrive at the truth and to put measures in place that ensure Palestinian-Egyptian relations are protected."

Cairo has long had cool relations with Hamas, which shares roots with the banned Egyptian opposition movement the Muslim Brotherhood. But Egypt, the first Arab state to make peace with Israel, is also keen to avoid being portrayed as an ally of the Jewish state in its conflict with the Palestinians.

(Editing by Alastair Macdonald and Tim Pearce)