A terrorist campaign unleashed by the Basque separatist organization ETA to drive the tourists off Spain's Mediterranean beaches continued unabated today with further bombings on the Costa del Sol as political violence escalated in other regions.

Two bombs, both small explosives that caused no injuries but extensive damage, exploded in hotels in the resorts of Torremolinos and Fuengirola brining to the 13 the number of explosions on the coast in the past week.

As on previous occasions, a coded telephone call by ETA to the authorities gave police ample time to evacuate the area. At both resorts, thousands of panic-stricken tourists were cleared from the beaches and the hotels and cafeterias on the promenades. Only two slight injuries have resulted.

In Madrid, the parliamentary spokesman for the government party was gunned down, apparently by ETA men, outside his home late last night. Congressman Gabriel Cisneros, 38, was recovering yesterday from a bulet wound in the stomach and said to be out of danger.

In the horthern Basque country, ETA commando groups machine-gunned the barracks of the Civil Guard rural police force in two small towns today while in a third town, the fishing port of Renteria near the French border, police withdrew from their barracks in a move to defuse a growing confrontation with the local population.

According to government sources, the beach bombs on the Mediterranean coast form part of a well-planned attack on the vital tourist industry. For the past decade, it has been a main source of Spain's foreign exchange. Last week, the bombers laid their charges in Malaga, Torremolinos, Marbella, Benidorm, Castellon and Pensicola, deep in the heart of the once flourishing industry.

The Costa de Sol, centered on Torremolinos, and the Costa Blanca, centered on Benidorm, some 200 miles further north on the Mediterranean coast, with their highrise hotels and apartments, are established destinations for European charter flights.

Although hotel operators say there have been only individual cancellations, a spokesman for the Costa del Sol hotel association admitted that further terrorist activity could be the death knell for an already struggling industry.

Tourism has been hit recently by high prices, water shortages last year in Benidorm and labor disputes.

Early reports on the tourist prospects for this summer reported that bookings were down 30 percent in certain areas even before the terrorist campaign.

The attack on the congressman in Madrid marked another departure in ETA's tactics. Cisneros, a prominent member of the ruling Union of the Democratic Center Party, is the first parliamentary victim of ETA violence. Until now, the Marxist-led organization has chosen Basque rightists, senior military officers and policemen as their targets.

Speculation in government circles focused on the possibility that Cisneros was sigled out bedause he represents the province of Soria, the site of a jail where more than 200 suspected ETA men are being held awaiting trial. A major ETA demand is that the Soria prisoners be relwased.

Cisneros is also known for his hardline views on the subject of Basque home rule, currently being debated by a committee in congress. The ruling party is holding out against demands by Basque nationalists for wide-ranging self-government and argues that such a move would pave the way for secession.

The machine-gun attacks by ETA commandos on the Civil Guard outpost of Vergara and Portugalete, near the Basque town of Bilbo, caused no injuries.

In the village of Renteria, a hotbed of ETA sympathizers and militants, police pulled out last night to a barracks considered better defended, near the city of San Sebastian. The withdrawal was marked by a spontaneous fiesta in the village, with wine and dancing in the streets and an impromptu fireworks display.

Government sources believe that the ETA campaign on the coast and elsewhere will intensify as the home rule debate continues through this month in congress.