As businesses across the country remain closed and big events are canceled for the foreseeable future, federal authorities are warning of the potential for terrorists to strike inside the U.S. during the coronavirus pandemic.The U.S. Department of Homeland Security wants grocery stores, gas stations and even COVID-19 testing sites to be aware that they could be targeted, though such an event may be unlikely."Now is the time to engage community businesses and other stakeholders to encourage vigilance and awareness," the DHS's assistant director for infrastructure protection, Brian Harrell, said in a statement to ABC News The U.S. Cybersecurity and Infrastructure Security Agency, Harrell's division within the DHS, on Friday issued a nationwide notice saying law enforcement should remain "alert for potential individuals triggered by the pandemic to inflict further harm."While there is "currently no imminent or credible threats," the alert noted that there has been an increase in online hate speech "intended to incite violence and/or use the ongoing situation as an excuse to inflict hate."As venues and "public gathering areas" remain closed, the alert stated that environments for a potential threat have shifted "to COVID-19 mobile screening stations, gas stations, still-open houses of worship, grocery stores, and other retailers that have been approved to do business.""If they're terrorists, they're usually looking for some place where they're going to cause a lot of mayhem, death and destruction,"said Hal Kempfer with Global risk Intelligence Planning.