GAZA, Sept 3 (Reuters) - A young man has died after setting himself on fire in the Gaza Strip, apparently in protest at economic hardship in the Palestinian enclave, the man's family and police said on Monday.

Ehab Abu Nada, 18, left his home on Thursday after an argument with his father, who had urged him to find work to help feed his poor family.

Frustrated in his job hunt, Abu Nada doused himself in petrol and set himself alight inside Gaza's main Shifa hospital.

His neighbors suggested he might have chosen to immolate himself at the hospital because he had wanted to make a gesture rather than kill himself, but medics there could not save him.

He was pronounced dead on Sunday.

He left to seek work and he did not come back. My heart was shattered, his weeping father told a local radio station.

We live in a miserable condition. We live in a rented house and I hardly can afford the rent, he added.

A police official from the Islamist Hamas movement, which rules Gaza, said an investigation was under way into Abu Nada's death, citing unemployment as his possible motive.

Abu Nada's suicide was another sign of frustration over the lack of work in the coastal territory, where a Gazan man set himself ablaze last year in despair but survived.

The teenager's death is reminiscent of the self-immolation of impoverished Tunisian fruit-seller Mohamed Bouazizi in December 2010, which sparked an uprising that toppled Tunisia's president and ignited protests across the Arab world.

Two suicides-by-fire in neighboring Israel this year have coincided with lingering social justice protests.

But few Gazans anticipate any broad unrest as a result of the case in the desperately poor but heavily-policed Strip, which has endured an Israeli economic blockade for years.

A U.N. report published last week said poverty stood at 40 percent among Gaza's 1.6 million people, of whom 80 percent depended on outside aid. It said nearly 30 percent were jobless.

It was unclear how Abu Nada's death would affect the policies of Gaza's Hamas rulers, who took over Gaza in 2007 after a brief civil war with forces loyal to President Mahmoud Abbas's Fatah movement, which holds sway in the West Bank.

Palestinians claim both territories, including East Jerusalem, for a future state, an aspiration hampered by the Fatah-Hamas rift, as well as by Israel's claim to all of Jerusalem and its occupation of the West Bank.

Many Gaza and West Bank residents blame the political division for tearing apart Palestinians' social fabric, dimming hopes for statehood and hamstringing the economy. (Reporting by Nidal Almughrabi; Editing by Alistair Lyon)