A huge firefight erupted between Israeli military forces and Palestinian militants in the occupied West Bank city of Jenin Monday, leaving at least three Palestinians dead, authorities said.

The Palestinian Ministry of Health said of the three dead, one was a teenager and more than two dozen were wounded in the clashes.

Israeli Air Force attack helicopters opened fire from the skies over Jenin to help Israeli troops leave the city, the Israel Defense Forces (IDF) said.

It was the first time since the Second Intifada that Israeli helicopters had opened fire while evacuating wounded troops, Israel Army Radio reported. The Second Intifada -- a major Palestinian uprising -- ended in 2005.

Army Radio said the wounded Israeli soldiers had been successfully evacuated.

The Jenin Brigade, a locally based militant group, said its fighters had fired at an Israeli helicopter, forcing it to retreat, and said they had managed to immobilize Israeli military vehicles with gunfire and ambushes.

The firefight was still ongoing as of 10:45 a.m local time (3:45 a.m. ET), doctors speaking on Palestine TV said.

The Palestinians killed included two men in their 20s: Khalid Azam Asa'asa, 21, and Qasam Faisal Abu Seriya, 29, and teenager Ahmed Youssef Saqer, who was 15, the Palestinian Health Ministry said, citing hospitals in Jenin.

Some 31 Palestinian people were wounded, including a girl with a critical head injury, the ministry said.

The IDF and Border Police said they were carrying out an operation to arrest two wanted suspects in Jenin when "a massive exchange of fire took place."

They were attacked with gunfire and hurled explosive devices and responded with live fire, hitting people, the IDF said.

An IDF vehicle was hit by an improvised explosive device on the way out, video from the scene showed.