(Adds Hamas ambush)

GAZA, April 15 (Reuters) - Israel's air force attacked two Palestinian militants as they rode a motorcycle through the northern Gaza Strip on Tuesday, killing one and wounding the other, Hamas police officials said.

They identified the casualties from the missile attack in Jabalya refugee camp as members of Islamic Jihad, one of several Palestinian factions fighting the Jewish state. An Israeli military spokeswoman confirmed an air strike had taken place.

Hours later, Hamas fighters ambushed Israeli troops carrying out a cross-border incursion. There were casualties on both sides, Hamas officials said. The military spokeswoman said one soldier was wounded in the clash and evacuated to hospital.

The violence could affect Israel's decision to renew some fuel supplies on Wednesday to Gaza through Nahal Oz, a border crossing that was shut after Palestinian gunmen attacked it last week. Two Israelis and four Palestinians died in that incident.

Nahal Oz is the only terminal for piping fuel to Gaza's 1.5 million Palestinians, who have come under stepped-up Israeli-led sanctions since Hamas seized control of the territory last June.

Palestinian officials in Gaza said Nahal Oz's closure would force the territory's only power plant to be shut down, causing sweeping blackouts.

Officials with the European Union, which supplies fuel to the Gaza plant, have said there should be enough fuel to last until Wednesday or Thursday.

Israel accuses Hamas of preventing distribution of fuel in order to create a crisis to pressure Israel to ease its blockade.

Israel frequently raids Gaza in it calls an effort to stop cross-border rocket fire and other attacks. (Editing by Matthew Jones)

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