Palestinian gunmen shot and killed an Israeli army lieutenant on patrol in the southern Gaza Strip on Wednesday, and Israeli troops fatally shot a 19-year-old Palestinian in the West Bank.

The lieutenant died after Israeli soldiers came under fire as they were searching for tunnels near the Egyptian border, a frequent area of clashes in 21 months of fighting, officials said on condition of anonymity.

In the West Bank town of Nablus, Israeli soldiers fired live ammunition at a group of children and teenagers who threw stones at tanks as they passed by the Askar refugee camp, residents said. The army said it was checking the report.

Hospital officials in Nablus said Rami Kotosh, 19, died from a bullet in the chest. Two others were slightly wounded.

Israeli forces routinely search and have sometimes destroyed houses in the area, saying they are used to cover snipers and conceal the entrances to tunnels used to smuggle arms and drugs under the border from Egypt into the Gaza Strip.

The Al Aqsa Martyrs Brigades, affiliated with Palestinian leader Yasser Arafat's Fatah movement, claimed responsibility for the shooting in announcements at several mosques in Rafah, in southern Gaza.

The shooting came amid new efforts to resume high-level talks between the two sides, with Foreign Minister Shimon Peres meeting for a second day Tuesday with Palestinian Cabinet ministers.

Those talks, stalled for months, were launched ahead of a meeting in New York next week of the "Quartet" officials from the United States, Russia, European Union and United Nations who are trying to bring an end to the conflict.

Also ahead of the meeting, Arafat sent a letter to the Quartet members assuring them of his commitment to reform the Palestinian Authority's security, financial and judicial sectors, Palestinian Information Minister Yasser Abed Rabbo said Wednesday.

He told reporters in Ramallah that for the reforms to be continued, "there must be an Israeli action in return lifting the curfew and stopping the collective punishment for the Palestinians."

In other violence, a Palestinian bystander died Tuesday during a shootout between Israeli police and a Palestinian gunman near Herod's Gate, one of the entrances to the Old City of Jerusalem.

And in the West Bank, an activist with Islamic Jihad who was planning a mission against Israeli targets was shot and killed, Palestinians said, blaming Israel. Israeli military officials said they were investigating.

Also Tuesday, Israeli police raided the campus of Al Quds University, in the village of Abu Dis on the edge of Jerusalem, and closed down the office of the president, Sari Nusseibeh, who is also the top PLO official in Jerusalem.

Nusseibeh is one of the most outspoken moderates among prominent Palestinians, criticizing suicide bombings and calling on his people to give up their long-standing demand for the right of all Palestinian refugees to return to their original homes in Israel, on condition that Israel give up all the West Bank, Gaza Strip and east Jerusalem.

Nusseibeh was in Greece when the raid took place. Israeli Internal Security Minister Uzi Landau said the university is part of the "long arm of the Palestinian Authority, operating against the law."

Israel and the Palestinians have conflicting claims over Jerusalem. Israel claims the whole city as its capital, but the Palestinians want the eastern part, captured by Israel in the 1967 Mideast war, as their capital. Israel says that under interim peace accords, the Palestinians are banned from political activity in Jerusalem, and police periodically close down their offices.

Despite the raid, Peres pursued his contacts with new ministers in Arafat's Cabinet, re-establishing contact that had been all but stopped during 21 months of violence.

Tuesday's meeting was with Interior Minister Abdel Razak Yihiyeh and Local Affairs Minister Saeb Erekat, who has also served as a senior negotiator in past talks with Israel. On Monday, Peres met Palestinian Finance Minister Salam Fayed.

Peres, from the moderate Labor party, has been pushing for restoring contacts with the Palestinians, against the resistance of hawkish Prime Minister Ariel Sharon, who has vetoed peace talks until all Palestinian violence stops.

Erekat said that at the Tuesday meeting, the Palestinians demanded an end to the Israeli military takeover of seven of eight main Palestinian towns and cities, while the Israelis raised demands to stop Palestinian suicide bombings and other attacks.

Peres' office said the meeting was positive, and both sides recognized the need to continue the talks.