Pope John Paul II today bluntly told the 20-year-old polygamist king of this tiny mountain country that God intended a husband to have only one wife. The pontiff, who arrived from Lesotho this morning, was escorted by spear-carrying warriors and soldiers with machine guns into a soccer stadium to celebrate Mass. He first was driven in the wrong direction, then slipped off a platform, without injury. Then the Mass was interrupted by the arrival of King Mswati III of Swaziland, who rolled into the stadium in a Lincoln limousine to the whistles of the crowd. A turret manned by a soldier with rifle and binoculars topped the altar, where a cross was stamped with a spear, shield and war ax. Mswati acceeded to the throne two years ago. He has four wives and is engaged to a fifth. ``Christians find that a monogamous marital union provides the foundation upon which to build a stable family in accordance with the original plan of God for marriage,'' the pope told a crowd of about 10,000 people. ``Hence, any forms of disregard for the equal dignity of men and women must be seen as serious contradiction of the truth that Chirst, the king of peace, brought into the world.'' Vatican sources said John Paul had been warned by local prelates to tread carefully before addressing the issue. King Mswati, wearing red-and-white robes and with five bird feathers decorating his head, listened expressionless to the pope's admonission. At the end of the Mass, in an unscheduled breach of protocol, the king formally thanked the pope for his visit. The two met later at the royal palace. Earlier today, red-coated soldiers greeted John Paul at the international airport of Manzini. When he arrived at the stadium, the pope's open car mistakenly drove out the gate, to the dismay of the spear-carrying warriors and Vatican security men. After returning to the stadium, the pope slipped off a platform on the soggy field before climbing onto the altar. He was not injured. On Thursday, in Maseru, Lesotho, John Paul told about 15,000 young people at a rally to ``renounce every form of violence and hatred'' in southern Africa. Organizers expected 1 million people at the rally and blamed a bloody bus hijacking, rainy winter weather and expensive accommodations _ such as $25-dollar-a-night tents _ for the small turnout. The pope visited the Queen Elizabeth II Hospital in Lesotho Thursday to comfort 20 survivors of the hijacking, many still shaken from the shootout that ended their 27-hour ordeal. ``I am saddened to learn that others on their way to join me on this pilgrimage have been victims of a hijack that has caused such anguish and ended in bloodshed,'' John Paul said Thursday, the day after police stormed the bus in Lesotho with four hijackers and 71 hostages aboard, including nuns and schoolchildren. All four hijackers and two passengers, including a 14-year-old girl, died in the exchange of gunfire Wednesday between authorities and the hijackers, officials said. Twenty others were injured. The government said police stormed the bus after the hijackers ordered the driver to crash the vehicle through the closed gate of the British High Commission. The gunman called for a return to civilian rule in Lesotho. They also demanded to meet the pope, King Moshoeshoe II and the high commissioner. After his eight-hour visit to Swaziland today, John Paul was scheduled to continue to war-torn Mozambique, the last stop on his 10-day tour of five southern African countries. The pope also went to Zimbabwe, Botswana and made a brief unscheduled stop in South Africa, where his plane was forced to land because of bad weather. Swaziland, a country of 700,000 people wedged between South Africa and Mozambique, is a dual monarchy under the king, offically known as ``the Lion,'' and a queen mother, named the ``the Great She Elephant.'' Polygamy is permissable, although most men have only one wife. King Sobhuza II, the current king's father, had more than 50 wives during his 60-year reign, which ended with his death in 1982.