Israeli warplanes today destroyed the personal headquarters here of Yasser Arafat, chairman of the Palestine Liberation Organization, in a daring precision attack that required midair refueling to reach the target 1,500 miles from home base.

Hours after the six-minute, mid-morning bomb and missile attack on the seaside complex 21 miles south of Tunis, the official Tunisian news agency TAP said the death toll had reached more than 50. Earlier, a PLO spokesman provisionally put casualties at 156 without providing a breakdown between the dead and wounded.

Arafat, who reportedly was at another PLO site, was not injured, although there were indications that the raid was timed to kill him. Witnesses said his L-shaped headquarters building had all but disappeared into a deep crater.

Israeli officials said the raid was in retaliation for the assassination in Cyprus last Wednesday of three Israelis at the hands of Palestinian gunmen, although the PLO had denied involvement. Defense Minister Yitzhak Rabin said it was a warning to terrorists "that the long arm" of Israel's military will reach them wherever they are. Details on Page A20.

The raid, Israel's first outside the Israeli-Lebanese region since 1981, brought wide condemnation from Arab countries, including Egypt, from U.N. Secretary General Javier Perez de Cuellar, and from several Western European capitals.

But in Washington, President Reagan and other U.S. officials strongly defended the Israeli raid, with White House spokesman Larry Speakes calling it "retaliation against a terrorist attack" and "a legitimate response and an expression of self defense." Details on Page A20.

The Tunisian government tonight asked the U.N. Security Council to meet to discuss the raid, which Tunisian Foreign Minister Beji Caid Essebsi said was a case of state terrorism aimed at sabotaging Middle East peace efforts.

The number and types of warplanes used were not known and Israeli military statements about the raid gave no details, although Israeli television said that they had been refueled in the air for their 3,000-mile round trip.

Witnesses here told reporters that they counted six planes, which some said were F4 Phantoms. But the Palestinian news agency WAFA said eight U.S.-made F16s were involved in the attack, which heavily damaged or destroyed buildings used by Force 17, the PLO's elite security wing blamed by Israel for the Cyprus killings, while leaving others in the complex untouched.

A visibly affected Arafat, who visited the scene in early afternoon but made no statement, was reported to have been in Marsa, a northern suburb of Tunis, when the attack began at 10:07 a.m., diplomats said. Tunisian sources said there had been plans for Arafat to preside over a meeting with Force 17 officials between 9 and 11 a.m.

Since Arafat moved his headquarters to Tunisia after the Israelis forced the PLO to leave Beirut in 1982, various Palestinian offices have been purposely dispersed into many neighborhoods to avoid running the risk of the Israelis' destroying all the leadership at once.

Tunisian witnesses said two Israeli aircraft remained high in the sky while the others attacked in pairs with air-to-ground missiles. WAFA said 500-pound bombs, some of them delayed-action, also were dropped.

Diplomats quoted Tunisian military sources as saying Israeli planes reportedly started skimming just above the Mediterranean when they reached the island of Malta, 250 miles to the east, to avoid radar detection.

Tunisian radar screens picked up the intruders only minutes before they attacked, the diplomats added.

Except for frequent raids into Lebanon, today's was the first abroad by Israel since their aircraft destroyed a French-built nuclear reactor near the Iraqi capital of Baghdad on June 7, 1981.

In a mission comparable to today's for precision and surprise, Israel rescued a planeload of Israeli hostages at the Entebbe, Uganda, airport, 2,200 miles from Israel on July 4, 1976, but it used an airport in neighboring Kenya as a staging area.

The pinpoint precision of today's raid was reminiscent of some Israeli bombing during the siege of west Beirut in 1982. Then, several buildings thought to have been regularly used by Arafat were destroyed -- sometimes within minutes of his reputed departure -- while adjoining structures were left untouched.

Diplomats credited the Israelis with almost perfect timing, noting that Israeli intelligence apparently had learned that Arafat, ever wary and secretive about his travels, had flown back from Morocco only last night.

Palestinian sources said the Israeli raid today should silence Arafat's critics among the PLO dissidents who have accused him of wanting to sell out to Israel by entering peace negotiations with King Hussein of Jordan.

In the attack cited by Israel as provoking the retaliatory raid, three Israelis -- two men and a woman -- were killed in their yacht in Larnaca, Cyprus, by three pro-Palestinian gunmen, who are now in Cypriot custody. Israel has blamed Force 17, and a caller to a western news agency in Jerusalem claimed responsibility for the slayings on behalf of Force 17.

But Arafat's wing of the badly split PLO has denied responsibility for the killings, and one of the gunmen told reporters, "We belong to no organization."

The government of Cyprus said Monday that from its investigations and interrogation of the three alleged assailants, one of them a Briton, "so far, no evidence has emerged leading to the conclusion that some organization" was involved. Some Palestinians later charged that the Israelis were espionage agents, but Cypriot officials have said they have found no evidence that they were.

Diplomatic sources warned that the United States might be accused of collusion with Israel in the raid. They reasoned that many Tunisians would question whether the U.S. 6th Fleet, which is reported to be off the Tunisian shore as a show of support for Tunisia in a current dispute with Libya, had been able to detect the Israeli intruders and could have alerted Tunisia.

Military sources noted, however, that unless the Israelis had been detected at higher altitudes while still in the eastern Mediterranean, even sophisticated equipment aboard the U.S. vessels would have had trouble picking up the Israeli aircraft in their low-level approach.