Israeli warplanes bombed smuggling tunnels along the Gaza-Egypt border Wednesday as U.S. President Barack Obama's new Mideast envoy said ceasefires declared by Israel and Hamas must be consolidated.

The Israeli air strikes come a day after an Israeli soldier was killed and three others injured in a roadside bomb explosion along the Israeli-Gaza border.

Shortly after the deadly explosion, Israel sent tanks and bulldozers into northern Gaza to plow up the attack site and launched an air strike that wounded a Hamas militant "who was prominent in the organization accountable for the attack," the military said. Hamas said the Israeli strike injured one of its men as he rode a motorcycle in the southern Gaza town of Khan Younis.

Reuters reported a little-known Islamist group has claimed responsibility for the attack on the Israeli soldiers, but the news agency didn't give the group's name.

Reflecting the seriousness of the situation, Israeli Defence Minister Ehud Barak cancelled a planned trip to Washington this week to stay home and deal with the crisis, defence officials said.

The violence has rattled the shaky calm between Israel and Hamas, the Palestinian militant group that controls the Gaza Strip. Each side separately declared a ceasefire on Jan. 18 following a 22-day campaign of Israeli air strikes and Palestinian rocket attacks.

The offensive has killed 1,285 Palestinians, more than half of them civilians, according to records kept by the Palestinian Centre for Human Rights. Thirteen Israelis, including three civilians, were also killed during the fighting.

Ceasefires must be consolidated: envoy

Obama, who has pledged to listen to all sides in the conflict, sent U.S. Mideast envoy George Mitchell on an eight-day visit to meet with leaders in the region.

Mitchell on Wednesday called for a consolidation of the ceasefires following talks with Egyptian President Hosni Mubarak in Cairo.

"It is of critical importance that the ceasefire be extended and consolidated, and we support Egypt's continuing efforts in that regard," he said.

"The United States is committed to vigorously pursuing lasting peace and stability in the region," Mitchell said, adding that his visit, which comes so soon after Obama's inauguration last week, "is clear and tangible evidence to this commitment."

Mitchell, a former U.S. senator, helped resolve the conflict in Northern Ireland and headed a commission that made Israeli-Palestinian peace recommendations in 2001.

He will also meet with outgoing Israeli Prime Minister Ehud Olmert in Jerusalem and Palestinian President Mahmoud Abbas in the West Bank. Mitchell will not meet with representatives of Hamas.

At his West Bank headquarters, the pro-Western Abbas said Tuesday he was looking forward to working with the new U.S. administration.

http://www.cbc.ca/world/story/2009/01/28/gaza-tunnels.html