Jersualem ? A Palestinian roadside bomb killed an Israeli soldier patrolling the border with Gaza on Tuesday, and Israel responded with an airstrike that wounded a Hamas militant in a flare-up of violence that undermined a cease-fire on the eve of a visit by the new U.S. Mideast envoy.

Israel briefly sent tanks and bulldozers across the border into Gaza after its soldier was killed and three others were wounded in the bombing. Hamas said the Israeli airstrike wounded one of its militants as he rode a motorcycle in the southern Gaza town of Khan Younis.

It was the worst bloodshed since the sides declared the cease-fire on Jan. 18 to end a three-week Israeli offensive.