JERUSALEM (AP) _ Israel today deported to Lebanon four Palestinians accused of fomenting the unrest sweeping the occupied territories, the army said.

The Israeli decision to expel the Palestinians had been condemned by other countries, including the United States.

An army official said the four, all natives of the West Bank, were flown by helicopter to a mountain pass 1 1/2 miles north of Hasbaya in south Lebanon. The official spoke on condition of anonymity.

The military command said in a statement:

''The deportees are among the leaders of the instigators and organizers of the disturbances in Judea and Samaria (the West Bank) in the past weeks.''

Five other Palestinians are appealing deportation orders issued Jan. 3.

Today's deportations were conducted in secrecy and no word leaked out until after they were completed.

Israel has deported more than 1,000 alleged troublemakers from the West Bank and Gaza since it occupied them the 1967 Middle East War, including 13 last year.

The most prominent among the newest deportees is Jabril Mahmoud Rujub, 35, who at age 17 was ordered jailed for life for membership in a guerrilla cell of the Palestine Liberation Organization.

In prison, Rujub led hunger strikes and wrote three political tracts widely circulated among prisoners. Freed in a 1985 prisoner exchange, he returned to the West Bank and recently published a book about prison life. Entitled ''Cell No. 704,'' it was a best-seller in the West Bank.

Besides Rujub, those deported today were:

- Jamal Mohammed Jibara, released in the 1985 prisoner exchange after serving six years in prison for recruiting PLO activists and planning terror attacks.

- Bashir Ahmed Al Kheiri, 45, an attorney from Ramallah who spent 15 years in jail as a PLO recruiter.

- Hussam Abdul Rahman Khader, 25, jailed for 18 months in 1985 as a PLO recruiter. The army accuses him of initiating most of the disturbances in the West Bank refugee camp of Qalqiliya since his release in July 1987.

A PLO spokesman in Baghdad, Iraq, said the deportations would not end unrest in the occupied territories.

''This oppressive Israeli action will not put an end to the people's uprising,'' the spokesman, Bassam Abu Sharif, said in a telephone interview. ''Our decision is clear. Our revolution will continue and the only solution is that the occupation itself should end.''

The riots began Dec. 8 in the occupied territories when rumors spread that a traffic accident that killed four Arabs had been planned to avenge the slaying of an Israeli businessman.

Thirty-four Palestinians have been killed by Israeli gunfire since Dec. 8.