For the first time, Americans become the victims in Gaza

US citizens are now having to bear the harsh consequences of being perceived as dangerously pro-Israeli by the Palestinians

The front end of the four-wheel-drive had been torn off and twisted back on itself, so that the front wheels stuck up in the air over the remains of the back. There was blood all over - American blood - and Munir al-Dweik, a Palestinian, said he found a severed leg with a black boot on the foot lying in the dust. There was a crater three feet deep where the explosives which killed three American embassy staff went off yesterday.

Scenes like this happen in Israel and the occupied territories all the time. People die violently almost every day in Gaza. Only last weekend two Palestinian children were killed in an Israeli army incursion. But this was the first time Americans have been successfully targeted here since the intifada began three years ago. Suddenly, the Americans find they are the targets. And that is something that will change the conflict.

American diplomats who came to inspect the damage were stoned by a crowd of Palestinians. So were journalists, which is unusual in Gaza, where Western reporters are generally welcomed.

The convoy was believed to be that of John Wolf, the American envoy sent to oversee implementation of the "road-map" peace plan, but Mr Wolf was said not to be in the convoy, but out of the region.

The road where the explosion took place is the main road south towards Gaza City from the crossing with Israel at Erez. Diplomats, journalists and aid workers all travel down it routinely and the explosives were hidden under a section of rough dirt road, where anything could be easily buried. The Palestinian police blamed a mine and the detonation was by remote control. The car in which the Americans were travelling was clearly identifiable with white Israeli diplomatic plates.

Faiz Dughmesh, a Palestinian who witnessed the explosion, said the Americans' GMC four-wheel-drive was the second vehicle in a convoy. In front was a Palestinian police car. He saw the Palestinian car pass safely then, as the GMC slowed to get across the rough road, the explosion went off.

This is not the first such incident here. Palestinians said that some three months ago a similar attack was attempted against cars carrying foreign diplomats just 500 metres away on the same road, but there were no casualties.

Anger is building up against the United States among Palestinians who say it is hopelessly biased in favour of Israel. There were murmurings in the crowd yesterday that the Americans deserved what they got. The attack came just hours after the US vetoed a UN Security Council resolution condemning the "separation fence" Israel is building deep inside the West Bank.

But the mood of Gaza cannot be based solely on those who turned up to celebrate. "We are not against the US," one man insisted. "The attack must have been intended for the Israelis and gone wrong."

There will be immediate suspicions of Palestinian militant groups, particularly Hamas and Islamic Jihad, were responsible. But those groups have been in retreat in recent weeks, particularly Hamas, after the Israelis assassinated several of its leaders, and it would be odd for either group to pick a head-on fight with the Americans now.

There will also be suspicions that al-Qa'ida, or an associated group, was behind the attack. Israel has been claiming since last year that al-Qa'ida has cells operating in Gaza but no one has ever come up with any evidence to back this claim up. Al-Qa'ida does not have strong support among Palestinians, who tend to a more dilute, nationalist interpretation of Islam than al-Qa'ida's Wahhabi extremism.