A US-trained military expert disputed on Wednesday an Israeli claim that it had nothing to do with an explosion that killed eight Palestinian beachgoers in the Gaza Strip last Friday, an incident that has turned a critical spotlight on Israel's military practices.

In this image taken from the video of a Ramattan Studios television news cameraman made available Tuesday June 13, 2006, Palestinian girl Houda Ghalia, 10 years, weeps next to the body of her father Ali, left, after an explosion killed eight civilians on a beach in Beit Lahiya, in the northern Gaza Strip,Friday, June 9, 2006. An Israeli probe of a blast that killed eight Palestinian civilians on a Gaza beach is expected later Tuesday June 13, 2006. [AP]

Israel released results of its own inquiry, which determined that the blast was not caused by a shell fired from Israeli artillery.

But Marc Garlasco, a military expert from New York-based Human Rights Watch, inspected the damage, the shrapnel and the wounds and came to a different conclusion.

"I'm convinced this was from an Israeli shell," Garlasco said Wednesday in a telephone interview. He said the main question still open is where it came from and when - was it fired by an Israeli artillery piece, as Palestinians charge, or was it buried in the sand, either on purpose by militants, as Israel alleges, or left over from an earlier attack?

Garlasco was the first independent expert to examine the scene, though Israel has doubts about his conclusions and about Human Rights Watch. He was in Gaza doing research for the human rights group when the explosion killed eight people on Friday afternoon, seven of them relatives.

Garlasco is a former intelligence specialist battle damage assessment officer for the Pentagon who has studied conflicts in Bosnia and Iraq. He rankled the Israeli government with a highly critical HRW report on destruction of houses in the Rafah refugee camp in Gaza in 2004. Israeli officials consider the human rights group biased in favor of the Palestinians.

Garlasco said he concluded the explosion was caused by a 155 mm shell of the type Israel uses. He viewed shrapnel collected from the scene by a Palestinian ordinance disposal unit, and in X-rays of Palestinians wounded in the blast.

Maj. Gen. Meir Klifi, who headed the Israeli investigation, said tests on the shrapnel removed from the body of a girl in an Israeli hospital proved it was not from a shell.

"I'm sure that all over that beach there is shrapnel," he told The Associated Press on Wednesday. "So no wonder that there is 155 mm shrapnel to be found."

Israeli army spokesman Capt. Jacob Dallal said Wednesday that the beach area is used by militants, so "this is also a battleground. This area is used for terror groups to launch (rockets) on Israel," noting that a rocket was fired from the area on Wednesday.

Garlasco said more work needs to be done before a solid conclusion can be drawn.

Israeli analyst Gerald Steinberg, who heads a watchdog group called NGO Monitor, charged that Garlasco is not a credible expert, and Human Rights Watch officials have "a long and carefully documented history of exploiting human rights claims to promote a clear anti-Israel political and ideological bias."