Reporting from Khartoum, Sudan, and Jerusalem — A Sudanese official said Thursday that hundreds of people were killed early this year when foreign warplanes bombed three convoys smuggling African migrants through Sudan along with weapons that apparently were destined for the Hamas-ruled Gaza Strip.

Israeli Prime Minister Ehud Olmert hinted at his air force's possible involvement in the attacks. They came after Israel ended a 22-day assault on Gaza without fully achieving one of its aims: to choke off Hamas' weapons supply.

Israeli officials have said that the militant Islamic group is seeking more powerful weapons than the crude Kassam rockets and Grad missiles it fires at Israeli towns.

An Israeli role in the bombings, if confirmed, would underscore the Jewish state's determination to strike far beyond its borders to protect its security. It also would be seen as a warning to Hamas' most powerful patron, Iran, which Israel alleges is developing a nuclear weapon.

The bombings brought a new layer of tragedy to Sudan, a country in the grip of an armed insurgency. The victims were migrants from Sudan, Ethiopia and other African countries seeking a better life in Israel or Europe, and young men and boys working as porters and drivers for the smugglers.

Fatih Mahmoud Awad, a spokesman for Sudan's Transport Ministry, said as many as 800 people died in the attacks in January and early February. He said each convoy had more than a dozen vehicles.

The Associated Press quoted a Sudanese Foreign Ministry official, Ali Youssef, as saying there were conflicting reports of the number of casualties.

Transport Minister Mubarak Mabrook Saleem discussed the attacks at a news conference this week in Khartoum.

The attacks were not reported in the country's newspapers, suggesting that the government was embarrassed to acknowledge that its sovereignty and air space could be violated so easily.

Saleem told the Associated Press that he believed the planes were American, but other officials said they were not identifiable.

The U.S. military Thursday denied having made any recent airstrikes on Sudan.

CBS News reported Wednesday that Israel carried out the bombing in January. The network said Israel had learned of plans to move weapons north through Sudan to Egypt, then across the Sinai and through tunnels into Gaza.

Salah Bardawil, a senior Hamas official, denied that the vehicles hit were bearing weapons for Gaza.

Thirty-nine people in the 17-truck convoy were killed, CBS said. Awad, the Transport Ministry spokesman, put the death toll at 14. Reuters news agency said two warplanes hit the convoy in a desert region northwest of Port Sudan on the Red Sea coast.

Awad said 17 people were killed three weeks later in a second strike. The third attack caused many of the smuggled weapons to explode and was by far the deadliest, he said.

The weapons were "modern and expensive-looking," he said, and "were headed for Gaza probably."

Israel's military refused to confirm or deny a role in any of the bombings.

But Olmert, speaking at an academic conference, said:

"We operate everywhere we can hit terror infrastructure -- in close places and in places farther away. Wherever we can hit terror infrastructure, we hit them and we hit them in a way that increases deterrence."

Olmert, who is scheduled to step down as prime minister next week, made the remark during a speech summing up his accomplishments. He said Israel had acted beyond its borders in "a series of incidents," a reference widely understood to include the bombing of an alleged Syrian nuclear facility in 2007 and the assassination of a top Hezbollah warlord in the Syrian capital last year.

Experts said Israeli warplanes had the range to fly the 1,680-mile round trip to Sudan.

Before ending the Gaza assault Jan. 18, Israel secured pledges from the United States and other Western nations to share intelligence on arms smuggling into Gaza and cooperate in blocking it.

Amnon Lipkin-Shahak, a former Israeli army chief of staff, said Israel would have needed such help to locate smuggling convoys in Sudan.

Israeli officials say some Gaza-bound weapons move by sea from Iran to Yemen and others are purchased in Sudan's flourishing arms market.

Both routes converge over land through Sudan into Egypt and are used for smuggling migrants as well as weapons.

Reva Bhalla, a Washington-based analyst with the private intelligence firm Stratfor, said Iran pays for the weapons and often sends agents of Hezbollah, the Lebanese militia, to buy them in Sudan and to hire the smugglers.

Sudanese official Awad blamed the government for neglecting eastern Sudan, driving youths into the smuggling trade. Those killed "were boys, many 12 or 13 years old, looking to earn some money," he said.

After the attacks, relatives and tribesmen began searching for loved ones, he said.

"We missed our people and started investigating. We eventually found the wreckage."