The Swiss foreign minister, Joseph Deiss, has condemned Saturday's bomb explosion on the Indonesian island of Bali which killed more than 180 people.
Calling the blast an "abominable crime against innocent people", Deiss called on the authorities to act quickly to find those responsible.
No one has so far claimed responsibility for the explosion, which happened late on Saturday night when a car bomb was detonated outside a packed nightclub in the popular Kuta Beach area of Bali.
One Swiss citizen - a 20-year-old woman from canton Graubünden - is confirmed dead, and the Swiss consulate in Bali says two other Swiss are missing, presumed dead. One is thought to be the 25-year-old partner of the Graubünden victim.
Five other Swiss are among the hundreds wounded in the blast, two of whom are in a serious condition, and were to Singapore for emergency treatment.
The Indonesian authorities have described the bombing as the "worst act of terror" in the country's history.
Speaking on Swiss television, Deiss condemned the bomb blast "in the strongest possible terms", while the United States denounced it as a "despicable act of terror".
"Shocked and horrified"
Kofi Annan, the United Nations secretary-general, said he was "shocked and horrified" at the nature of the attack and called on the international community to work together in the war against terrorism.
Swiss tour operators said all of their clients currently on holiday in Indonesia and Bali had been accounted for.
Indonesian police also reported another bomb explosion near the United States consulate in Bali shortly after the first blast, but there were no reports of any casualties.
Muriel Berset-Kohen, a spokeswoman for the foreign ministry, said the Swiss government had informed the families of the Swiss victims of the attack.
The 2002 Swiss president, Kaspar Villiger, sent a telegram of condolence to the Indonesian authorities.
Officials said many of those killed in the attack were Australian tourists, but there were also a number of victims from other nations including Germany, Sweden, Canada, Britain and Italy.
The explosion comes three days after the United States government issued a worldwide alert against possible terrorist attacks.
The incident has heightened fears that Indonesia - the world's most populous Muslim nation - is being used as a base for terror activities by members of the al-Qaida network.
In light of the attack, the Swiss foreign ministry is advising people not to travel to Indonesia unless absolutely necessary.
The Swiss division of the German tour operator, TUI, has cancelled all scheduled tours to Indonesia until at least October 21.
swissinfo with agencies
The bomb went off shortly before midnight local time on Saturday night.
More than 180 people - including one Swiss - were killed in the blast.
No one has so far claimed responsibility for the attack.
Many of those killed in the blast were young foreign tourists on vacation.
Indonesian police have described the attack as the "worst act of terror" in the country's history.
The Swiss foreign minister, Joseph Deiss, condemned the nightclub attack "in the strongest possible terms", while the United States denounced it as a "despicable act of terror".