RAMALLAH, West Bank – Palestinian Arab leader Mahmoud Abbas, under growing pressure to rein in terrorists, ordered his security forces yesterday to prevent attacks on Israel and investigate a deadly shooting of Israeli civilians last week.

But Palestinian Arab security officials were short on details about possible actions against armed groups, and a spokesman for Hamas said his terrorist group would continue attacks.

The order by Mr. Abbas, approved by his Cabinet, was the Palestinian Arab leadership’s first step against terrorists since six Israelis were slain Thursday at the Karni crossing between Israel and the Gaza Strip.

“A decision was taken that we will handle our obligation to stop violence against Israelis anywhere,” Cabinet minister Saeb Erekat said.

While Israel’s government cautiously welcomed the announcement, it remained unclear how far Mr. Abbas was willing to go. He has insisted he will use persuasion, not force, to get terrorists to halt violence.

Palestinian Arab ministers said Mr. Abbas planned to travel to Gaza today, a day earlier than initially planned, for talks with two terrorist groups, Hamas and Islamic Jihad.

Mr. Abbas’s victory in the January 9 election for president of the Palestinian Authority raised hopes for a breakthrough in Middle East peacemaking because he has been an outspoken critic of violence and is eager to resume negotiations with Israel.

But the Karni attack, two days before Mr. Abbas was sworn in, swept away Israeli goodwill, and Prime Minister Sharon suspended contacts with Mr. Abbas.