LOUISVILLE, Ky. — A Christmas morning explosion in Nashville, Tenn., has caused phone outages across the state of Kentucky.

911 services in many counties spanning from western to eastern Kentucky are down and residents are encouraged to look online for their local law enforcement or emergency numbers in order to get ahold of them.

A recreational vehicle parked in the deserted streets of downtown Nashville exploded early Christmas morning, causing widespread communications outages that took down police emergency systems and grounded holiday travel at the city's airport.

Authorities said they believe the blast was intentional. Officials also said no additional explosive devices have been found — indicating no active threat to the area. Investigators have received around 500 tips and leads.

“It’s just going to take us some time,” Douglas Korneski, the special agent in charge in charge of the FBI’s Memphis field office, said at a Saturday afternoon news conference. “Our investigative team is turning over every stone” to understand who did this and why.

Federal agents converged Saturday on the home of a possible person of interest in the explosion as investigators scoured hundreds of tips and leads in the blast that pulverized city blocks and damaged dozens of buildings.

Kentucky State Police is also reporting problems at Post 1 in Hickory, Post 3 in Bowling Green, and Post 16 in Henderson. Information on how to contact KSP can be found here.

AT&T has been experiencing outages affecting the entire state and a spokesman for the company said it is working around the clock on recovery efforts.

“It is a big operation with the building itself where we’re trying to at least get the generators back in order so that the mobile phones will be back into operation and then we’re hoping within the next day or, if we’re fortunate, it may take one or two days to get everything back online,” Swann said. “But they’re here to work with us and we’re hopeful we’ll get that back established.”

T-Mobile services have also been hit with interruptions. A tweet from chief technology officer Neville Ray said the company’s restoration efforts also continue around the clock, and if possible, customers should use Wi-Fi to make phone calls.

911 services in Louisville and Lexington have not reported any issues, but some businesses in those cities are having problems with phone services and may be unreachable until service is restored.

Spectrum services have not experienced any interruptions related to the explosion.

The Associated Press Contributed to this report. This is a developing story.