A combined force of leftist paramilitary police and armed civilians attempted a coup against the government of Gambia early this morning while President Dawda Jawara was in London attending Prince Charles' wedding ceremonies.

Jawara said in a British Broadcasting Corp. interview this evening, however, that the coup "has not succeeded yet," and loyalist forces were reportedly still fighting the rebels in the Gambian capital of Banjul. Jawara said he had received reports from Banjul during the day in two telephone conversations with his vice president.

Gambia, a small West African nation of about 600,000 population, leapt briefly into the consciousness of the American public several years ago as the land to which author Alex Haley traced his African forebears, an event recorded in his bestselling book "Roots."

Gambia's radio, which was in the control of the rebel forces and announced victory, identified the leader of the coup as Kukli Samba Sanyang, whose party, the Gambian Socialist Revolutionary Party, was banned by Jawara's government last fall following the assassination of the director of the country's 900-man police force.

A group of about 300 policemen who serve a parliamentary function and are called the field force were reported to be fighting on the side of the rebels. The country has no army.

In his London interview, Jawara said policemen who remained loyal to his government were resisting the takeover.

[British diplomats monitoring the coup attempt from Dakar, Senegal, said three persons, "all among the military," had been killed in fighting, The Associated Press reported.]

Jawara said the vice president was operating between the president's downtown office building and police headquarters and that in that section of town "the situation is under control."

Jawara, a strongly pro-Western leader, indicated tht he might ask President Abdou Diouf of neighboring Senegal, which has a mutual defense arrangement with Gambia, to intervene with troops. Last October, Jawara requested Senagalese help after denouncing an alleged plot inspired by Libya to destabilize his government. About 150 paratroopers were flown into Banjul by Senegal and stayed for two weeks.

Jawara said he intended to return to Gambia tonight, possibly via Dakar. News services later reported that he left London aboard a Senegalese jet.

Repeated rebel radio broadcasts requesting blood donations and calling for medical personnel to report to the city's main hospital fed speculation here that the fighting was heavy.

The Jawara government last fall charged that Sanyang's party was involved in the alleged Libyan plot against it.

In their broadcasts. the rebels said they have established a ruling body called the National Revolutionary Councilheaded by Sanyang and composed of eight additional civilians and three members of the field force. There were also reports of looting in downtown Banjul.

The rebels said they were installing "a dictatorship of the proletariat" and charged Jawara's "bourgeois and oligarchic" government with "nepotism, injustice, tribalism and corruption."

The rebels said they had closed the airport, all of the country's border entry points and cut telecommunications -- a claim seemingly contradicted by Jawara's reported telephone calls to Banjul.

Gambia, which gained independence from Britain in 1965, has been one of Africa's rare multiparty democracies. Jawara, the former colonial prime minister, continued in that office after independence and became president in 1970.

A poor country, Gambia recently suffered two years of poor peanut harvests, its major revenue-earning export, and a sharp decline in domestic food production caused by insufficient rains.

Residents of Banjul, whose per capita income is about $210, had recently complained about inflated prices for food and consumer items brought about by a yearly influx of 60,000 tourists from the Scandinavian countries. As recently as last week, there were reports of demonstrations in the capital over the scarcity of basic foodstuffs.