A Palestinian negotiator has accused Israel of stepping up attacks on the Palestinians ahead of Wednesday's visit to the region by US President Bush.
An Israeli soldier detains Palestinians in Gaza
Saeb Erekat said the peace process could not be successful unless there was "a stop to [Israeli] settlements and Israeli escalations".
Earlier, Israeli Prime Minister Ehud Olmert threatened increased attacks against militants in the Gaza Strip.
He was speaking after a Gaza rocket landed the farthest ever inside Israel.
The rocket fired by Palestinian militants last Thursday reached the town of Ashkelon, about 15km (nine miles) from Gaza, the Israeli army said. No-one was hurt in the attack.
In a separate development, Israeli troops raided Gaza on Sunday, killing four people, including two civilians, Palestinians said.
An Israeli military spokeswoman said troops shot several gunmen, Reuters reported. She had no immediate word on the civilian casualties.
Mr Erekat condemned recent Israeli raids in the occupied Palestinian territories, saying that they threatened the peace process in the Middle East.
Mr Erekat said Israeli actions threatened the peace process
He said Palestinian leader Mahmoud Abbas would demand that they be immediately stopped at planned talks with Mr Olmert on Tuesday.
Mr Erekat was speaking just hours after the Israeli leader said Palestinian militants in Gaza, controlled by hardline group Hamas, were to blame for provoking a heightened response from the Israeli army.
Citing the Ashkelon attack, Mr Olmert said that "there is no doubt that this signals a certain escalation in the activity of terror organisations in Gaza".
"The defence ministry has instructed the security services to strengthen Israel's reaction, which has already been firmer in recent weeks," Mr Olmert said.
The violence will not make life any easier for President Bush, who is heading to the Middle East with the hope of pushing forward the search for peace, the BBC's Andrew Craig says.
Mr Bush had hoped for a full peace agreement before leaving office in January 2009.
In an interview on Israel's Channel 2 TV on Sunday, Mr Bush said he could not predict such an accord would be finalised by then.
He said: "There'll be an agreement on what a [Palestinian] state would look like, in my judgment. I am not going to try to force the issue because of my own timetable, but I do believe that Prime Minister Olmert and President Abbas do want to get this done."