GAZA (Reuters) -- A Gaza cease-fire is closer to unravelling despite efforts by U.S. President Barack Obama's Middle East envoy to reinforce the fragile truce.
Palestinian militants in the Hamas-ruled Gaza Strip fired two rockets into Israel -- the first since a January 18 cease-fire -- and Israeli aircraft then attacked a metal workshop in the enclave that the military described as a weapons factory.
No one was injured in the attacks, but a surge of violence over the past two days threatens to reignite a war that Israel launched on December 27 with the declared aim of ending crossborder rocket fire.
Former U.S. Senator George Mitchell, Obama's envoy, planned to meet Palestinian President Mahmud Abbas in the occupied West Bank following talks on January 28 in Egypt, which has been trying to broker a long-term truce, and Israel.
Mitchell, repeating Obama's call for a return to peace talks, said it was "of critical importance that the Gaza cease-fire be extended and consolidated."
But with an election approaching on February 10, Israeli leaders have been talking tough on security, a main voter concern.
They have pledged a forceful response to an explosion that killed an Israeli soldier on the Gaza border on January 27 and to the rockets.
Palestinian militants said the rockets were payback for Israel's killing of three Palestinians since the truce began.
'Hamas Must Learn'
"Hamas has to know that these rockets are their responsibility and they will learn that shooting rockets into Israel is simply not in their interest," said Mark Regev, a spokesman for Prime Minister Ehud Olmert.
Some 1,300 Palestinians, including at least 700 civilians, were killed during Israel's 22-day offensive in the Gaza Strip, according to the Hamas-run Health Ministry in the territory.
Israel put its losses at 10 soldiers and three civilians.
In Jerusalem on January 28, Mitchell said any durable truce must end smuggling into the Gaza Strip and reopen border crossings to relieve Israel's economic blockade of the enclave, where half the 1.5 million population depend on food aid.
Olmert told Mitchell that Israel would not reopen any Gaza crossings, except for aid shipments, until an Israeli soldier captured in 2006 was freed, an Israeli official said.
Israeli opposition leader Benjamin Netanyahu, who tops opinion polls ahead of the election, saw more violence ahead.
"It's clear Hamas is rearming. Of course, it's attacking us. Of course, it's trying us," Netanyahu told Israel Radio. "The next government will have no choice but to finish the work and remove the Iranian terror base for good."
Israel has secured U.S. and European pledges to help to prevent Hamas, which it says receives weapons from Iran, from rearming through tunnels under the Gaza-Egypt border and by sea.
It has lobbied its Western allies to put pressure on Cairo to better seal its border with the Gaza Strip.
Israel tightened its blockade of the Gaza Strip after Hamas seized the territory in internal fighting in 2007, and the tunnels have been the only way for Gazans to get access to the commercial goods that Israel keeps out.