Wrapping up a four-day Mideast shuttle Monday, an American envoy failed to win agreement from Israelis and Palestinians on U.S. peace proposals. The deadlock triggered new clashes between Palestinian stone-throwers and Israeli troops.

Protesters chanted "Death to America" and burned U.S. flags. In the West Bank towns Bethlehem and El Bireh, Israeli troops fired tear gas and rubber-coated steel pellets at hundreds of Palestinian students, injuring several.The U.S. envoy, Dennis Ross, was to meet one more time with Israeli Prime Minister Benjamin Netanyahu Monday night before returning to Washington to brief President Clinton.

Ross has been trying to win support for a U.S. proposal for an Israeli withdrawal in stages from 13.1 percent of the West Bank, with each step accompanied by Palestinian security gestures.

Netanyahu denied Israeli media reports that a compromise was being worked out and that he had increased his initial withdrawal offer from 9 percent to 11 percent.

"We have not discussed specifics on percentages, and therefore reports of a supposed agreement are not true," Netanyahu said, adding that he did not expect Ross to conclude a deal on this trip.

Palestinian officials said they were concerned that the United States was ready to modify its initiative under Israeli pressure.

"We feel that this is a real test for American political will and the ability to withstand Israeli intransigence," said Hanan Ashrawi, a Palestinian Cabinet minister.

In a U.S.-backed agreement signed last year, Netanyahu pledged to carry out three troop pullbacks by this summer. However, he later said he would go ahead with only one withdrawal before launching talks on final borders. The Palestinians have said they would not accept any changes in signed agreements.

Netanyahu hinted Monday that he was softening his position, saying he was ready to discuss an additional withdrawal with the Palestinians. However, the Pal-es-ti-nians reportedly insisted that the Americans be present at such talks, an idea Netanyahu rejects.

Palestinian leader Yasser Arafat blamed Israeli obstinacy for stalling the peace process and called on U.S. officials to keep pressing for a settlement.

In the Netherlands, Arafat urged the United States to deploy "its international and regional weight to protect the peace process from impending failing."

But Ross, in Egypt Monday, renewed suggestions that the United States could end its effort to renew peace talks. His comments follow statements by other U.S. officials that American patience is running out.

In a demonstration of how violent the climate is, a carload of explosives that authorities believed was meant for use in a terrorist attack went off prematurely Sunday in the West Bank town of Ramallah. A Palestinian man was killed.

Palestinian police rounded up several supporters of the Islamic militant Hamas group for questioning Monday. Israel TV's Channel Two said the car was loaded with 110 pounds of TNT. The force of the blast reduced it to a pile of twisted metal and leveled the garage it was hidden in.

Netanyahu denied a report in the Maariv daily that he was considering a partial freeze on Jewish settlement construction in the West Bank in exchange for Palestinian acquiescence to a large-scale Jewish housing project on disputed land in Jerusalem.