A series of bomb blasts on Spain's Eastern Mediterranean coast today appeared to signal the start of terror campaign by Basque separatists seeking the release of jailed members of ETA organization.

No one was injured in four separate bomb blasts, Which occurred after the ETA warned authorities to clear the target areas. The bombings, aimed at sabotaging Spain's vital tourist industry, appeared timed to cause the Spanish government maximum embarrassment at a time when President Carter was paying an official one-day visit to Madrid.

The blasts had been expected since Tuesday when the government rejected ETA ultimatum threatening to bomb the holiday resorts if its demands were not met. Government spokesman said the Cabinet would not give in to blackmail, and the firm stand was endorsed by a unanimous all-party vote in Congress last night.

The blasts were a repetition of a similar campaign along the coastal resorts last year masterminded by the "political-military" faction of ETA, an acronym for Euzkadi Ta Askatasuna (Basque Homeland and Liberty). The faction was responsible for 14 explosions in resorts last July for bombs placed at Madrid's airport and two main railway stations that left seven dead and scores injured.

An estimated 2,500 tourists and local residents were evacuated during the night from the main resort area of the town of Alicante. A bomb exploded there early in the morning, damaging the fifth floor of a luxury hotel on the Mediterranean. Three more explosions took place north of Alicante in the small resort town of Javea, where whole areas also were evacuated.

In an apparently unrelated terrorist attack, a business executive was shot to death in the Basque town of Vitoria. Police believed he was the victim of the "military" faction of ETA, which has claimed responsibility for the majority of the more than 60 political killings so far this year in Spain.

Foremost among the current demands of the terrorists is the release of 19 ETA members who are either serving long prison sentences or awaiting trial on a variety of charges ranging from murder and kidnaping to bank robberies. Several of the 19 are also due to stand trial in connection with last year's campaign directed at the resorts.

The ultimatum sent by ETA to the government also demanded that the warden of a prison were most ETA members are jailed be replaced and that the government pave the way for the disputed border province of Navarre to be absorbed by the existing three Basque provinces. The Complex issue of Navarre, half of whose population is Basque, has headed most disputes between the government and Basque naionalists.

Hotel owners and tourism authorities expressed great concern over the effect of the new bombing campaign on one of Spain's major sources of foreign exchange. Tourism was already down 6 percent in the first quarter of this year, and in some resort areas visitors and bookings are down as much as 25 percent.

The ETA has threatened intermittent bomb blasts throughout the summer all along the Mediterranean coast.

An extreme right-wing terror organization calling itself the Basque-Spanish Battalion responded to the ETA camaign by warning that it would place reprisal bombs along the northern Basque coast beaches. The group has been responsible for about a dozen murders of ETA members and sympathizers this year in an escalating struggle that has become a new feature in the Basque problem.

Leaders of the moderate Basque Nationalist Party, which has a majority in the Basque autonomous parliament formed after local elections earlier this year, appealed in vain to the ETA to call off its bombing campaign. The ETA rejects antonomy and is fighting for an independent Basque Marxist state.