Despite a government blockade to cut their key supply line from neighboring India, Tamil guerrillas say the flow of arms and men has continued from across the Palk Strait dividing India and this Indian Ocean island nation.

The guerrillas are fighting to carve a separate state in the northern quarter of Sri Lanka. They rely heavily on shipments from guerrilla redoubts along the Indian coastline that they say have been only marginally interrupted.

"Before, you could decide to go across at 5 o'clock and go at 6. Now you have to plan ahead a little," said Sunder, a Sri Lankan Tamil guerrilla, referring to the timing of the fishing vessels and small motorboats that make the 18-mile run.

Sunder and other guerrillas were interviewed in southern India. All insisted on the use of a nom de guerre, and agreed to meet with a reporter only on condition that the specific location of the interview not be disclosed.

With expanding guerrilla attacks straining their Army, Sri Lankan officials here increasingly point a finger at southern India where they say Tamil separatists operate training and logistics camps.

Separatist political leaders interviewed in Madras, the capital of the southern Indian province of Tamil Nadu, say government charges about Indian training bases are grossly exaggerated. But they hinted at the existence of rebel military activity in south India.

One guerrilla who identified himself as Skantha said: "We are training for a long drawn-out struggle like in Nicaragua. The emphasis is on training and equipping a people's army. We believe when we take the forces on, we must be able to defend ourselves.

"We come to India when things get hot and also to meet outsiders. We can't get international attention if we stay only in Jaffna."

Sri Lankan officials said the rebels operate at least half a dozen secret training camps in India in the jungle along the desolate Tamil Nadu coastline, from Point Calimere, which juts into the Indian Ocean toward Jaffna Peninsula, to Rameswaram, the departure point for the now-suspended ferry service between the two countries.

The training camps, Sri Lankan officials said, provide terrain similar to that in much of Sri Lanka, are enthusiastically backed by the local Indian Tamils and are remote enough not to visibly embarrass New Delhi.

The Indian government has repeatedly denied allegations by the Sri Lankan government that it condones or even supports Tamil guerrilla training bases in southern India. It says it merely has given refuge to approximately 40,000 Sri Lankan Tamils who have fled the fighting in the northern provinces.

The 45 million Tamils in India share language and ancestry with Sri Lanka's 2.6 million Tamils, who have been involved in a 13-year conflict with the island's majority Sinhalese. India is pressing the Sinhalese government of Sri Lankan President Junius R. Jayewardene for a political settlement of the Tamils' longstanding demands for autonomy.

One political leader, Appapillai Amirthalingam, secretary general of the mainstream Tamil United Liberation Front, which does not maintain a military wing, said most of the training camps are in Sri Lanka. "Maybe 30 or 40 boys come and rent a house and maybe they are training some," he said. "But I know the Indian government is not training them. With the entire population of Jaffna [almost entirely Tamil] behind them, they can have training camps anywhere there."

Another leader, M.K. Eelaventhan, general secretary of the Tamil Eelam Liberation Front, which maintains a guerrilla force in northern Sri Lanka, said in an interview in Madras: "The boys are not being trained here. They may be doing some on their own, but not with the help of the Indian government."

Eelaventhan, a former economist with the Sri Lankan central bank, acknowledged, however, that "if Tamil Nadu weren't available as a sanctuary, we would have had to fight it out in Jaffna and perhaps we would have been liquidated."

Although separatist leaders claimed to have about 10,000 trained fighters either in Sri Lanka or moving constantly between Jaffna and southern India, Indian intelligence officials and western diplomatic sources say the actual figure is closer to 2,000 and that many of them are not able to fight because of a shortage of arms.

The guerrillas interviewed claimed they are primarily using home-made weapons and weapons captured from Sinhalese troops. However, Sri Lankan officials here said that guerrillas are using AK47 assault rifles, G3 rifles and Indian-made self-loading rifles supplied from their contacts in Tamil Nadu.

Guerrilla commanders claimed to have obtained surface-to-air missiles for use against helicopter gunships employed by the Army.

Leaders of the guerrilla groups openly discussed training ties to various factions of the Palestine Liberation Organization and political contact with "friendly anti-imperalist groups," such as the African National Congress and the Zimbabwe African People's Union, but denied that they were receiving arms or direct financial assistance from the Soviet Union.