Natural disasters like Hurricanes Maria and Irma and the recent wildfires in California have led to a spate of warnings from countries that want to caution their citizens about the risk of traveling to the United States, but the advisories are also noting potential for violence in the wake of the Las Vegas shooting and the potential for terrorist attacks as well.

While warnings for travel to the United States aren’t new, they have picked up significantly in the last few weeks, following these events, said Ed Daly, who oversees the content for the Global Intelligence Division of iJET International, a travel intelligence firm based in Annapolis, Md. “After a lull, there was a rash of incidents which happened one after the other and led to these advisories,” he said.

On Oct. 16, for example, the Canadian government updated its travel advisory for the United States. In the safety and security section, the advisory says that travelers should be aware that, “The possession of firearms and the frequency of violent crime are generally more prevalent in the U.S. than in Canada.” In addition, it advised against nonessential travel to Sonoma, Napa and Lake Mendocino in the wake of recent wildfires in California and Nevada.

At least three of the newer travel warnings were related to Hurricanes Maria and Irma.

On its travel advice page for the United States, updated Oct. 13, the United Kingdom government says that “terrorists are very likely to try to carry out attacks in the USA” and that these attacks could happen “in places visited by foreigners.” In addition, it said, “The post-storm environment in Puerto Rico and the U.S. Virgin Islands remains particularly fragile, with continuing power outages and unstable buildings.”

The shooting in Las Vegas that left 59 people dead may have prompted some of the recent warnings.

On Oct. 3, the day after the incident, for example, the New Zealand government’s Safe Travel site updated its travel information to the United States. A statement under the section detailing crime says: “Active shooter incidents occur from time to time in the United States.” A sentence addressing the specifics of the shooting follows. The section also says that violent crime and gun possession are more prevalent in the United States than in New Zealand but adds that these crimes “rarely involve tourists.”

And on Oct. 10, Ireland’s Department of Foreign Affairs and Trade updated its United States travel advice page on its site; while the page doesn’t specifically mention the Las Vegas shooting, it does say that the United States has witnessed a number of mass shootings in recent years. In addition, the advisory says that there is an increased threat of terrorism and extremist violence worldwide which “should be borne in mind by Irish citizens living and working in the USA.”

And Germany’s travel advisory, updated on Oct. 13, warns of more political demonstrations and the increased danger of politically motivated violence in the United States. According to the advisory, German nationals should therefore, “particularly in urban centers,” monitor the news and avoid demonstrations on a long-term basis.

The advisory said, too, that, in the wake of Hurricanes Maria and Irma, its citizens should carefully examine the necessity and possibility of travel to Puerto Rico, the U.S. Virgin Islands and parts of Florida. According to the advisory, “There must still be flooding and landslides” in the affected areas.

Travel warnings to the United States peaked in the summer of 2016, according to Mr. Daly of iJET.

New Zealand, Germany, Canada and the United Kingdom were among the countries that issued warnings about the potential dangers of traveling to the United States; reasons included Zika in parts in Florida, the threat of terrorism and a shooting at a gay nightclub in Orlando, Fla., that left 49 people dead.

In the wake of the early July shooting and a racially fueled shooting in Dallas that left five police officers dead, for example, the Bahamas advised its young male citizens traveling to the United States to be especially cautious when interacting with police. “The Ministry of Foreign Affairs and Immigration has taken note of the recent tensions in some American cities over shootings of young black males by police officers,” the statement reads. “We wish to advise all Bahamians traveling to the U.S. but especially to the affected cities to exercise appropriate caution generally.”

The most recent warnings aside, Matt Dumpert, a senior director at Kroll, a security consulting company based in New York, said that warnings for travel to the United States had proliferated over all in the last few years. “Thanks to the amount of information available to travelers on social media, governments are issuing more and more official travel-related statements in an attempt to take care of their citizens,” he said. “The increase in these warnings does not mean that the U.S. is a more unsafe place to visit.”