Spain's lucrative tourism industry has long been a target for Basque separatist group ETA.
A British tourist was injured in Fuengirola in 2002
In 2001 the authorities spent nearly 2.6 million euros on improving security in tourist resorts after a series of bomb attacks, including attacks at a hotel in Salou and at Malaga airport.
The attacks continued in 2002 and the signs are that 2003 will follow the same pattern.
But commentators do not expect the bombs to have a major impact on the numbers of tourists visiting the country - whose custom is worth 44 billion euros a year.
"Attacks like these do not really register on the radar, to be honest," said a spokeswoman for the Association of British Travel Agents, Frances Tukes.
Facts of life
"You can sometimes see a dramatic drop-off very close to the event, but a couple of weeks later it is back to normal."
The impact of ETA bombs bears no comparison, she says, to that of the 11 September attacks, which was far-reaching.
Pituca Catou of the Spanish Tourist office in London says British travellers - who make up the largest single group of visitors to Spain - accept that isolated small-scale attacks are a fact of modern life.
"These things happen in all countries - and in Northern Ireland too," she says.
Tourism generates 9% of Spain's gross domestic product and employs 11% of the population.
About 48 million foreign tourists visit Spain each year.
Of these nearly 35% are British and 28% are German.
German travellers showed a greater tendency than their British counterparts to stay at home after 11 September.
Overall, there was a drop-off of between 4% and 5% in the family market - mainly package tours - in Spain in 2002, according to Frances Tukes.
Many Spanish resorts, which originally built their reputation on low-cost no-frills holidays, are trying to move upmarket in order to sustain visitor numbers.
TOP SPANISH DESTINATIONS
The UK Foreign Office points out that although hotels are sometimes targeted - possibly as part of ETA's attempts to extort money from hotel owners - the risks of being injured in an attack are not high.
"Despite the continuing threat, statistically your chances of being caught in a terrorist outrage remain very low," says the latest Foreign Office travel advice.
"But, given the many millions of foreign tourists who visit Spain each year, there will always be the chance of visitors... being in the wrong place at the wrong time."
One of the worst attacks against tourists came in 1997 when 35 British and Irish tourists were injured in an attack in Tarragona on the east coast.
In 2002, there were attacks in Santa Pola and Torrevieja on the Costa Blanca; Fuengirola, Marbella and Mijas on the Costa Del Sol; and Zaragoza and Santander in the north of the country.
In 2003, hotels have been targeted in Bilbao, Pamplona, Alicante and Benidorm.