Palestinian medical workers say an Israeli air strike near Gaza City Wednesday killed at least three Palestinians, including a teenager.

Witnesses say the air strike was aimed a car driving through the city.

Separately, in a pre-dawn raid in the West Bank, Israeli forces killed a wanted Islamic Jihad militant leaders and arrested two others.

Palestinians look at blood in street after Islamic Jihad leader Walid Obeidi was killed in Qanatiya, 16 Jan 2008

Islamic Jihad said its West Bank leader, Walid Obeidi, was killed during an exchange of gunfire with Israeli troops in a village, Qanatiya, near the town of Jenin..

Israeli forces frequently conduct raids in the West Bank and Gaza to hunt down militants involved in attacks against Israelis.

On Tuesday, the United Nations Special Coordinator for the Mideast Peace Process urged all parties to stop the escalation violence in the Gaza Strip controlled by Hamas.

Robert Serry made the appeal on one of the deadliest days of fighting between Israeli forces and Palestinian gunmen that killed at least 19 Palestinians, including three civilians.

Serry told reporters that the scale of the bloodshed is deeply alarming. He also said the Israeli military must ensure that its operations do not endanger civilians.

Nearly 50 people - both militants and civilians - were wounded during Tuesday's fighting in northern Gaza.

Palestinian President Mahmoud Abbas has condemned the Israeli operation saying, "it is impossible to bring peace under these circumstances."

Also Tuesday, a Palestinian sniper killed an Ecuadorian man as he worked on an Israeli farm near the Israel-Gaza border. Hamas claimed responsibility for the shooting.

Some information for this report was provided by AFP and AP.