The United States has said it still opposes Israel's policy of targeted assassinations, despite its apparent use of the same tactic to kill six al-Qaeda suspects in Yemen on Sunday.
"Our policy on targeted killings in the Israeli-Palestinian context has not changed," US State Department spokesman Richard Boucher said.
Mr Boucher refused to talk about the Yemen attack, but said that Washington's reasons for opposing the targeted killings of Palestinians might not apply in other circumstances.
Earlier, US officials said that America's Central Intelligence Agency (CIA) had carried out the Yemen attack, which reportedly killed senior al-Qaeda operative Ali Qaed Senyan al-Harthi.
The unmanned Predator B taxis back to a hangar in El Mirage, Calif., in this Sept.
6, 2001 file photo, after a test flight over the Mojave Desert. Opening up a visible
new front in the war on terror, U.S. forces launched a pinpoint missile strike
at a car in Yemen Monday Nov. 4, 2002, killing Qaed Salim Sinan al-Harethi, a
top al-Qaida operative, a U.S. official said. Al-Harethi's car was struck by a
Hellfire air-to-ground missile, believed to have been conducted by a CIA aircraft.
The CIA launches Hellfires from pilotless Predator aircraft. Hellfires can also
be launched by attack helicopters and are used by both the U.S. Army and Marine
Corps.(AP Photo/Doug Benc)
But neither the CIA, nor President George W Bush would comment publicly on the reports on the CIA's involvement.
The Yemen attack - apparently by an unmanned CIA plane - was similar to Israel's air raids on Palestinian militants, and the BBC's Nick Childs at the Pentagon says US officials now face some awkward questions about their opposition to Israeli actions.
Israel insists that its policy of targeted killings is pre-emptive self-defence, while Palestinians describe the killings as assassinations which violate basic human rights.
But using carefully chosen language, Mr Boucher denied allegation that by staging the Yemen operation the US may be using double standards towards Israeli policy.
"We all understand the situation with regard to Israeli-Palestinian issues and the prospects of peace and the prospects of negotiation... and of the need to create an atmosphere for progress.
"A lot of different things come into play there."
President Bush has repeatedly stressed his determination to destroy al-Qaeda, saying that "the only way to treat them is [for] what they are - international killers".
Our correspondent says that a Bush administration officials told the BBC that the US was engaged in a war, and that it was dealing with enemy combatants.
American officials have praised the Yemeni attack, which US Deputy Defence Secretary Paul Wolfowitz described in an interview with CNN as "a very successful tactical operation".
"One hopes each time you get a success like that, not only to have gotten rid of somebody dangerous, but to have imposed changes in their tactics and operations."
The six al-Qaeda suspects died when the jeep they were travelling in was hit by a missile fired from an unmanned CIA plane - believed to be a Predator drone.
The attack took place in the northern province of Marib, about 160 kilometres (100 miles) east of the capital Sana'a, and a Hellfire missile was reportedly used.
Yemeni sources said those killed included Ali Qaed Senyan al-Harthi, whom the US has linked to the attack on the warship USS Cole off Aden in October 2000.
The Yemeni Government has not yet confirmed Harthi's death, but Yemeni officials said he had been under surveillance for months and intelligence had been passed on to the Americans.
© 2002 BBC