RAFAH BORDER CROSSING, Gaza Strip (AP) – Israel reopened the only crossing for Palestinians from the Gaza Strip to Egypt after a three-week closure, but the army would not say Friday whether it found evidence of an alleged plot by militants to blow up the border terminal.

About 1,400 Palestinians crossed into Gaza after the Rafah terminal was reopened, a Palestinian official said. The three-week closure came during the peak summer season, and hundreds of stranded travelers slept on the ground near the desert post – the only crossing for Palestinian travelers in and out of Gaza.

Also, a top aide to Israeli Prime Minister Ariel Sharon warned of increased threats against Sharon.

“There has been a sharp increase in the level of threats against the prime minister,” said Dov Weisglass, Sharon’s bureau chief, in an interview with Israel’s Channel 2 TV – excerpts of which were aired Friday.

Weisglass did not name the source of the threats, but in recent weeks security officials have warned that Sharon could be a target of right-wing extremists who oppose his plan to withdraw from the Gaza Strip and four West Bank settlements.

Palestinian militants have vowed to strike at Israeli leaders to avenge Israel’s killing of militant leaders. Israel shut down the terminal July 18, saying it had intelligence information that Palestinian militants had dug a tunnel under the crossing or a nearby Israeli army outpost and planned to blow it up.

Soldiers searched the area during the closure, but the military refused to say Friday whether anything suspicious was found. The Israeli daily newspaper Haaretz reported on its Web site that U.S. pressure forced Israel to reopen the crossing.

While the terminal was closed, some 1,500 Palestinians waited nearby and 3,000 stayed others with relatives in Egypt or at hotels, said Salim Abu Safia, the Palestinian director of the Gaza crossing.

About 1,400 people crossed Friday, and two more days were needed to allow those who had been stranded to cross back, Abu Safia said.

Israel had offered to open an alternate crossing, but Egypt and the Palestinian Authority rejected that proposal as a violation of existing border agreements.

For many, Friday’s crossing was an emotional one, ending an ordeal that left them dependent on aid from charity organizations. Earlier this week, Egypt warned of an impending humanitarian crisis.

With tears streaming down her face, Nihad Abu Jazar, 22, a Cairo University student, ran into the arms of waiting relatives.

The travelers spent the first week sleeping on the ground, Abu Jazar said. Later, Egyptians authorities and aid groups brought basic supplies, including mattresses.

But there were not enough toilets, and people were forced to stand for hours waiting to use the bathroom.

She said she had considered returning to Cairo.

“But every time I convinced myself that they might open any time and, to be honest, I don’t have enough money. My father is unemployed,” Abu Jazar said.

Elsewhere in Gaza, a Palestinian trying to plant a bomb near an Israeli settlement was killed by Israeli army fire Friday, the army said. The 18-year-old was a member of the militant Islamic Jihad group, Palestinian officials said.

Later, troops fired on four Palestinians who approached the fence separating the Gaza Strip from Israel near the Sufa crossing, killing one and wounding and capturing another, the army said. Two escaped.

Also in Gaza, 5,000 Palestinians – including some 100 armed men- marched in an Islamic Jihad rally to honor a militant killed in an Israeli airstrike earlier in the week. The marchers burned Israeli and American flags and a model of an Israeli settlement.

In the West Bank, soldiers carrying out an arrest raid in the village of Salfit near Nablus shot and killed one Palestinian militant and arrested another as they tried to flee, the army said.

Later, the army found two pistols and hand grenades during a search, the army said. Palestinian officials identified the dead man as Mohammed Balasmeh, 23, from the militant Hamas group.

AP-ES-08-06-04 1640EDT