VIENNA, Austria (AP) _ A 26-year-old teacher became the fourth fatality in the Vienna airport attack when she died of grenade wounds suffered in the Palestinian terrorist raid, hospital and government sources said Friday.

There was no explanation for the delay in announcing the death Wednesday of Elisabeth Kriegler, who had been planning a trip to Israel and was caught in the Dec. 27 assault on the check-in counter of the Israeli airline El Al.

A simultaneous attack at the Rome airport left 16 people dead.

Doctors warned from the outset that the Vienna woman's head injuries were critical. She lapsed into a coma and never awakened. Her parents, who had accompanied her to the airport, were slightly injured.

The three others who died at Schwechat airport were Ekhart Karner, a Vienna high school teacher; Ely Gana, an Israeli citizen; and one of the three terrorists, who was killed in a shootout with police a mile from the airport.

The two surviving gunmen, believed to be members of the radical Palestinian faction of Abu Nidal, were injured and arrested. They are recovering in a Vienna prison hospital, said Andreas Rudas, a spokesman for Interior Minister Karl Blecha.

Rudas also said the two Palestinians, whose identity has not yet been determined because they traveled to Vienna on forged Tunisian passports, had made new ''important disclosures that, if they prove correct,'' would help Austrian authorities in their investigations. He did not elaborate.

According to the spokesman, only four or five of 46 people injured in the Vienna attack were still hospitalized. About 80 were injured in the Rome attack.