Relatives, Hamas leaders and other political faction chiefs greeted the body of Fadi al-Batsh as it entered Gaza through Egypt.

Al-Batsh's family said he would be buried later on Thursday, after Hamas officials had earlier said they would hold a large public funeral on Friday. It was not immediately clear why the timing of the funeral was changed.

Al-Batsh, a lecturer in electrical engineering at a Malaysian university, was killed by a pair of assailants on a motorcycle as he was walking to pray at a mosque on Saturday. Hamas has accused Israel's Mossad spy agency of being behind the killing.

"You are returning back to us ... paving the way for our return to Palestine," said Khalil al-Hayya, a top Hamas leader, at a small ceremony at the border crossing. The coffin lay on a table, wrapped in a Palestinian flag.

"To the occupation, we say the debt to us has become heavy," he said. "The day of punishment is coming."

Hamas has identified al-Batch as a commander in its military wing, but said little else about his activities. Israeli media have reported that he was involved in Hamas' military drone program.

Israel has a long history of assassinating wanted militants, though it rarely acknowledges responsibility. But in a published interview Thursday, Israeli Defense Minister Avigdor Lieberman said Israel did not do it.

"We did not assassinate him," Lieberman told the Arabic news site Elaph. When asked who killed al-Batsh, the minister said: "Ask James Bond ... maybe James Bond killed him like in the movies."

Israel and Hamas, a militant group sworn to Israel's destruction, are bitter enemies that have fought three wars since Hamas seized control of Gaza in 2007.

Tensions have heightened recently as Hamas has organized mass protests next to the Israeli border.

Earlier on Thursday in Gaza, hundreds of Palestinians took part in the funeral of a Gaza journalist who died after being shot by Israeli troops while covering a protest on April 13.

Ahmed Abu Hussein, 24, died from his wounds on Wednesday at an Israeli hospital, where he had been transferred.

Amateur video taken at the time shows him wearing a blue vest and helmet with the word "TV" on it. He appeared to be standing far from the Israeli border in a group of bystanders when he was shot.

In a statement Thursday, the Israeli military said "the circumstances regarding the injury of Ahmed Abu Hussein will be examined."

Thirty-five protesters, including two journalists, have been killed by Israeli live fire during the weekly demonstrations.

The Palestinian Health Ministry said Thursday that 21 of those wounded by Israeli fire in the protests have since had to undergo amputations due to their wounds. It said 17 lost legs and four lost fingers or parts of their upper limbs.

Rights groups, the U.N. and the European Union have all criticized Israel's use of live fire against unarmed protesters.

Israel says it is defending its border and accuses Hamas of using the demonstrations as cover to plan and carry out attacks.