Palestinian militants attacked a crossing on the border with the Gaza Strip on Thursday, setting off a clash with Israeli troops that thwarted the third such assault this week, the army said.

The army said troops killed one militant and wounded a second at Kerem Shalom, a crossing used to deliver humanitarian supplies into Gaza. A third militant escaped.

Gaza's ruling Hamas militant group is furious over Israel's economic blockade of the area and has threatened to violently break through the border to lift what it derides as the Israeli "siege." Militants consider the crossings humiliating symbols of Israel's economic blockade of Gaza.

Israeli attacks killed at least 20 Palestinians on Wednesday, the bloodiest day in Gaza in more than a month. Three Israeli soldiers were killed in a Hamas ambush.

Thousands of Palestinians, including journalists and members of rival political movements, marched through the streets of Gaza City Thursday at the funeral procession of a TV cameraman killed while covering the fighting.

Fadel Shana, a 23-year-old cameraman with the Reuters news agency, was struck, along with two bystanders, as he filmed Israeli tank movements off in the distance.

At the cameraman's funeral, Shana's body was wrapped in a bloodied Palestinian flag, as fellow journalists marched alongside carrying his broken camera and bloodstained flak jacket. The marchers waved Palestinian flags and carried small posters of Shana posing with his camera. "Fadal Shana, goodbye, the victim of the truth," the posters said.

Later, the body was taken to Shana's hometown of Khan Younis in southern Gaza. About 3,000 Palestinians attended the funeral. "Fadel, Fadel, loved by God!" the crowd chanted.

Young Palestinian men wailed in grief, and a woman on a balcony screamed and emotionally banged her hands on the railing. Gunmen fired into the air, and flags from the rival Fatah, Hamas and Islamic Jihad movements were seen.

Reuters released the video taken by Shana in the seconds before his death. The footage shows a tank on a distant hilltop open fire. A tank shell is seen flying toward the camera followed by a large explosion before the screen went black.

Pictures taken by colleagues after the attack showed his jeep on fire and Shana's body lying next to it along with several other bodies strewn along the road. Shana's jeep was marked "Press" and witnesses said the cameraman was wearing an identifying flak jacket.

Shana was killed near the Bureij refugee camp in central Gaza. He had been in the area to film the aftermath of a deadly Israeli airstrike that killed 12 Palestinians, including five children aged 12-15, according to medical officials.

The Palestinian Journalists Union declared a one-day strike to protest Shana's death. The Foreign Press Association, representing journalists in Israel and the Palestinian territories, expressed "profound sadness."

"His death is a stark reminder of the risks our Palestinian colleagues take every day to cover the news in Gaza," the FPA said.

Hassan Kashef, a prominent Gaza journalist, accused Israel of targeting Shana. "Israel fears the truth. And they want to kill the truth," he said. "And Fadel was killed while his camera was showing the truth."

The Israeli military said it was investigating the incident. It expressed sorrow over his death, but did not accept responsibility.

Despite near-daily Israeli-Palestinian violence, casualties among journalists are rare. Only three others have been killed covering the West Bank and Gaza Strip since 1992, according to the New York-based Committee to Protect Journalists.

Wednesday's death toll was the highest since a broad Israeli military offensive that ended in early March killed more than 120 Gazans, including dozens of civilians, over several days. Israel carried out the offensive in response to heavy rocket barrages on southern Israeli towns launched by the ruling Hamas militant group.

Since then, Israel and Hamas had appeared to be honoring an informal truce, though punctuated with Palestinian rocket attacks, some Israeli airstrikes and a deadly Palestinian attack that killed two Israeli civilians at a fuel depot.

Israel, which controls Gaza's borders, has greatly restricted the flow of goods into the area since Hamas seized control there last June. It has further tightened the blockade in recent weeks in response to the intensified rocket attacks from Gaza.

Meanwhile, Egyptian mediators were trying to negotiate a cease-fire between the two sides.

Palestinian President Mahmoud Abbas condemned the "Israeli aggression in Gaza" and urged all sides to "cooperate with Egyptian efforts."

But Hamas spokesman Sami Abu Zuhri said the violence cast doubt on Egyptian cease-fire efforts. "There can be no discussion of a truce in the midst of these crimes," he said, threatening revenge against Israel.

Hamas advocates the destruction of Israel while Israel considers Hamas a terror group.

In the West Bank Thursday, Israeli troops killed two Palestinian militants in a raid in the town of Qabatiya. Troops surrounded the hideout early Thursday, and exchanged fire for about an hour with the Islamic Jihad militants inside, before shooting them dead.

Abu Ahmad, an Islamic Jihad, spokesman vowed a shift retribution. "You will not escape the coming revenge," he said.