In the face of overwhelming numbers, a small band of mutinous soldiers for the past month has occupied a small town near the Ghanaian border and ignored demands to lay down their Libyan-supplied arms.

The impasse at the town of Po grew out of an ineptly executed pre-dawn purge by Upper Volta's conservative, pro-western senior Army officers against a group of radical, avowedly pro-Libyan junior officers. The tense standoff appears to be typical of Upper Volta, a West African country that prides itself on a record of three relatively bloodless military coups in 23 years of independence.

Events in Upper Volta show how fragile African governments are when beset by ideological divisions and how easily an outside power, in this case Libya, can manipulate such internal conflicts.

Moreover, the deadlock here reflects the generational differences afflicting the armed forces in many African countries, a fracture that contributed to uprisings in Ghana, Liberia, Gambia and Kenya.

In each case, junior officers sought to justify their revolt as the overthrowing of an older generation of entrenched, corrupt politicians and senior army officers. Since 1979, junior officers have succeeded twice in Ghana and took power in 1980 in Liberia, but were crushed severely in Gambia in 1981 and last August in Kenya. Domestic tension in each of the countries had been exacerbated by recession-battered economies before the upheavals, a circumstance that continues for most of black Africa today.

A landlocked West African country in the continent's semiarid Sahel belt, Upper Volta is listed by the world bank as one of the world's 15 poorest countries, with an annual per capita income of $210. Even before the global recession, the six-year Sahel drought that ended in 1974 had set back Upper Volta's meager economic growth by a decade, according to a western economist.

The country's Army came to power when the first independent civilian government fell in 1966 after a popular uprising and general strike. The uprising and strike were in protest against official corruption, readily noticeable amid the stark poverty here, and of increasing political restrictions. Since then, Upper Volta's senior Army officers and "old guard" politicians have dragged their 7.1 million compatriots through seven unstable governments while ineffectually grappling with the country's worsening economic problems.

The latest military government to emerge has its roots in an uneasy alliance between senior officers trained in the French colonial army and a small leftist group among the generally better educated junior officers who banded last November in a palace coup that overthrew Col. Saye Zerbo's discredited two-year-old military regime.

After forming an all-military, 120-member People's Salvation Council Assembly, they made the typical declaration that they took power to rectify the Zerbo regime's "corruption, irresponsibility and denial of fundamental rights." They also promised to establish a movement toward economic development, "true" democracy and political stability.

A mild-mannered Army medical doctor, Maj. Jean-Baptiste Ouedraogo, 42, was selected as head of state to represent the conservatives while a firebrand, charismatic leftist, Capt. Thomas Sankara, 33, was appointed as his prime minister to satisfy the coterie of radical junior officers.

Beginning in February, Sankara made his conservative Army colleagues nervous when his 48-hour scheduled stopover in Tripoli to see the Libyan leader, Col. Muammar Qaddafi, was prolonged to a week. The Salvation Council's promised stability began to unravel when Sankara's men ferreted out a since-questioned March countercoup plot among conservative Army and civilian leaders, about 15 of whom were arrested.

In virulent speeches denouncing "internal enemies of the people" such as traders, all religious leaders and "bourgeois" trade unionists, Sankara began to amass a popular following among Upper Volta's students and urban poor, while simultaneously alienating several levels of the general conservative Upper Voltan society, according to a well-informed Upper Voltan journalist.

The split came when Sankara invited Qaddafi to Ouagadougou for an official visit at the end of April, then notified the head of state of the visit fewer than 24 hours before the Libyan leader's arrival, Ouedraogo has said publicly.

Sankara already had praised Qaddafi's style of "people's revolution" in speeches, and after the April 30 visit, about 10 planeloads of Libyan arms were delivered to Ouagadougou's airport after dark, western diplomatic and informed Upper Voltan sources said. "Some of the arms made it down to Po to Sankara's Army commando supporters," added an informed western diplomatic source. Po is 87 miles south of Ouagadougou near the border with Ghana.

Two weeks later, the behind-the-scenes conservative strongman, Col. Yorian Gabriel Some, ordered a predawn roundup and arrest of the leftist junior officers. Troops missed radical Capt. Blaise Compaore, however. He escaped to Po and has since led the group of about 150 Army commandos loyal to Sankara in revolt against the country's 3,700-man Army.

Head of state Ouedraogo afterward dissolved the Salvation Council as a failure and ordered all troops back to their barracks. He appointed a 19-member, mainly civilian Cabinet, announced that a new constitution would be prepared within six months and that he would hand the government over to an elected civilian governemnt by November 1984.

In an effort to reconcile all of Upper Volta's disgruntled factions, on May 27 Ouedraogo ordered all military and civilian political prisoners released. This included Sankara and his radical colleagues. Sankara, however, was kept under house arrest but two weeks later was returned to barracks detention after allegedely trying to escape over the back wall of his house.

Throughout, the commandos at Po--half of whom are barely trained recruits--have remained in revolt. The rebels demand the unconditional release of Sankara, his reintegration into his commando unit and the reestablishment of the dissolved Salvation Council.

In a June 14 interview in his office, Ouedraogo denied that large, 1 a.m. troop movements--after the nation's curfew--south from Ouagadougou toward Po were a signal that he finally had run out of patience and was preparing to attack the rebels. "We are still on the way to resolve this matter in the most pacific manner possible and without a violent confrontation," Ouedraogo said.

Ouedraogo added that additional Libyan arms have crossed northern Ghana and were delivered to the mutinous troops at Po. Ghana's military ruler, Flight Lt. Jerry J. Rawlings, has developed close ties with Qaddafi since his second coup at the end of 1981. Libya is trying to exploit the Upper Voltans' differences among themselves to get the radicals into power, he said.

Ouedraogo said he did not know whether Qaddafi has Upper Volta earmarked as part of his envisioned revolutionary Libyan-led pan-African federation, but added that it is clear that "Qaddafi is trying to destabilize Upper Volta, and that is why he is sending arms here."