PARIS — France remained vigilant Friday following the terrorist attack at an American-owned industrial chemical plant near Lyon, but the men’s shows in Paris and the streets of the capital showed no signs of heightened security or a chilling effect.

The Fédération Française de la Couture, du Prêt à Porter des Couturiers et des Créateurs de Mode, France’s governing fashion body, has not issued any statement about heightened security in light of Friday’s incident. It had made such suggestions to fashion houses in January after 17 people were killed in Paris in attacks at satirical magazine Charlie Hebdo, on a police officer and at a kosher supermarket. Paris has been on highest alert since then and, in an unprecedented mobilization of the country’s armed forces on domestic soil, France deployed 10,000 troops to boost security.

The streets of Paris remained packed on Friday with tourists both taking advantage of the semiannual sales and visiting the city’s sites. Sweltering heat had many of them sitting at outdoor cafés whiling away the summer afternoon.

Meanwhile, the men’s shows stayed on schedule, with no signs of stepped-up security. Many attendees were still learning of the attack as of Friday afternoon.

The incident at the plant occurred Friday morning, when one person was decapitated and another two hurt, but the suspect was not successful in blowing up the Air Products factory.

There were terrorist attacks in two other countries Friday morning, as well — in Tunisia and in Kuwait. Meanwhile, France’s President François Hollande said early in the evening that he is raising the security alert to the highest level for three days in the southeastern region of France where the factory attack occurred.

Since January, there has been one more terrorist act in the country, in early February when three members of the military were killed outside of a Jewish center in Nice.