A Sudanese government minister has confirmed reports of an air raid in eastern Sudan earlier this year.
The minister, Mabrook Mubarak Saleem, told an Arabic news channel that many people had been killed in the strike, said to have taken place last month.
Israeli officials have not commented publicly on reports that their planes may have been involved.
Israel's Prime Minister, Ehud Olmert, did not confirm any raid but said Israel hit everywhere to stop terror.
"That was true in the north," said Mr Olmert, "and it was true in the south ... Those who need to know, know there is no place where Israel cannot operate."
Giving a speech in the coastal town of Herzliya, the outgoing prime minister said: "We operate in many places near and far, and carry out strikes in a manner that strengthens our deterrence."
The CBS television network said it had been told by American officials that a strike by Israeli planes in January had succeeded in preventing weapons from Sudan reaching Gaza.
Mr Mabrook Mubarak Saleem said those killed in the air raid had been civilians from a number of African countries.
'Nod and wink'
The BBC's Paul Wood in Jerusalem says Israel's response is following a traditional pattern, set when it attacked a suspected nuclear reactor in Syria in 2007, of first refusing to confirm an alleged strike and then giving a nod and a wink.
What we are getting now from Mr Olmert is clearly the nod and the wink, our correspondent says.
Much informed comment has appeared in the Israeli media, he adds, including the view of a retired general that Israel would not have had to violate anyone's airspace to carry out the strike, if it did.
Nonetheless it was a long way to fly and the assumption is that this was a serious target, our correspondent says, and that these were weapons that could have changed the game in the conflict between Israel and Palestinian militants.
They could have included surface to air missiles or perhaps missiles with a 70km (44-mile) range that would have enabled militants to hit Tel Aviv from Gaza, our correspondent adds.