Former Pakistani prime minister Zulfiqar Ali Bhutto was hanged before dawn today at the Rawalpindi jail, ending a long drama over his fate and opening the prospect of widespread unrest.

The government radio announced that the execution had taken place at 2 a.m. and that Bhutto's body was handed over to his relatives for burial. Members of the family were informed of the death early in the day by a senior military official.

Bhutto, 51, was sentenced to die along with four others for conspiracy to kill a political foe, but the sentence was delayed for agonizing weeks and months as appeal after appeal was filed in the courts and world leaders petitioned Pakistan's military leader and president, Gen. Zia ul-Haq, to show clemency.

Overthrown by the military almost two years ago following charges of election irregularities, Bhutto nevertheless retains a substantial following among the country's peasantry as a result of his charismatic rule from 1971 to 1977. There are fears that widespread violence could break out following his death.

Should Pakistan be thrown into an intense period of unrest, it would add yet another country in upheaval to a zone that runs from the Arabian Peninsula, through Iran to Afghanistan and Pakistan.

Despite the reports from official sources and family members that Bhutto had been hanged, the Pakistani government still had not made a formal announcement of his death.

The daily newspaper Nawaiwqt quoted the prison medical officer as saying, "Bhutto has breathed his last."

The execution was carried out in a secret military operation and the only people to be told other than the executioners were Bhutto, his wife and daughter. The women have been held under house arrest for several weeks.

Bhutto's wife and his daughter Benazir were allowed to visit at the jail for three hours yesterday, and diplomatic sources reported that they were told it was their last visit before the hanging.

Extraordinary precautions were taken in the capital and at airports yesterday, according to these sources.

Following the hangin, Bhutto's body was flown from a nearby airbase to his home village in southern Sind Province for burial.

Evidence that the hanging was imminent began to build just after midnight when armed troops surrounded the Rawalpindi jail. At 1:15 a.m., two journalists found watching the jail were arrested and taken to a police station. They were held there until dawn when the troops had dispersed.

The jail superintendent, Yar Mohammad Duriana, spent the night at the prison, according to aides. This would be the normal procedure when condemned prisoners are to be hanged.

Shortly after 4 a.m. and unscheduled flight took off from nearby Chaklala airbase, apparently carrying Bhutto's body to his home village of Ghari Bhutto, near the town Larnaka. A heavy concentration of troops was reported at both the village and at the town, and roadblocks had been set up.

Bhutto was convicted by the Lahore High Court of conspiring in 1974 to murder Ahmed Raza Kasuri, a formerally of Bhutto, Kasuri survived the ambush but his father, riding in the same car, was killed.

Throughout the court cases and appeals from world leaders Zia had consistently said he would abide by the decision of the court and send the former prime minister to the gallows if the judges so ruled. He stood firm despite appeals for mercy from a large number of world leaders, including President Carter, Saudi Arabia's King Khalid, British Prime Minister James Callaghan and China's Deng Xiaoping (Teng Hsiao-ping).

A Chinese military delegation was scheduled to leave Pakistan today, and the government is believed to the waiting for its departure before officially announcing the execution to spare the Chinese from commenting on it.

In addition to an expected reaction to Bhutto's hanging, Zia also has announced that elections are to be held in November to return the country to civilian rule.

Zia's announcement of elections brought the country full circle. It was massive political unrest that brought the army to power in July, 1977, in a coup that toppled Bhutto.

The election announcement came only a day before the Supreme Court announced last week that it had rejected Bhutto's lawyers' last appeals.

Throughout Bhutto's long trial and subsequent appeals, Pakistan was a country full of tension and rumor. Few were neutral about the flamboyant Bhutto. Members of his Pakistan People's Party, his supporters in Sind and others in rural areas stood by the former premier, even as he was in the prisoner's dock.

Equally as intense in their opposition to Bhutto were the many who suffered under his various reform policies, under the heel of the federal security police or at the prime minister's whim.

Hundreds of Bhutto's supporters reportedly have been jailed as a precaution against unrest.

At the end, Bhutto reportedly was a broken man, carrying nothing of the imgae of the Berkeley-and-Oxford-educated political sophisticate who was at home both in front of huge crowds or with world leaders.

A visitor to his cell this past week reportedly that he was a sick and gaunt man, his gums blackened from a debilitating disease and his spirits dashed. CAPTION: Picture, ZULFIQAR ALI BHUTTO . . . clemency appeals denied