Madison police still do not have much information on a bomb threat made to the Madison Metro transit system Sunday afternoon.

According to a police release, the dispatch center received a phone call around 3:40 p.m. saying a bomb was planted on a Madison Metro bus.

"Someone called the 911 dispatch [and said] that there was a bomb on a bus," Julie Maryott-Walsh, the transit's marketing and customer services manager, said. "Half an hour later, someone called again and said a bomb was then under another bus."

Maryott-Walsh said the buses involved were specific to Route 6, which runs from the West Side to the East Side of the city.

The city's transit system worked with city police to ensure public safety before investigating the bomb threats.

"We responded with a preliminary investigation," Madison Police Public Information Officer Mike Hanson said. "We worked with Madison Metro to identify [the buses involved] and make sure everyone was safe."

The first action taken, Hanson said, was evacuating the two buses that were identified as possibly carrying bombs. Primarily, police are concerned with making the bus safe, he added.

Sunday it involved removing passengers from the bus and keeping the community safe from possible harm.

Both Hanson and Maryott-Walsh could not provide information on how the bus drivers dealt with patrons on the buses, but Maryott-Walsh said she guessed the drivers were honest with the riders.

While the metro system has had some recent disturbances with fights on the buses and at transfer points in the past months, Maryott-Walsh reiterated the bomb threat was a rare incident, and threats of that nature have not occurred in recent years.

"I think, right now, it was just an isolated incident," she said. "It was a baseless threat."

Regardless of the one-time incident, Hanson noted the seriousness of the threat, and said police officers will always take similar calls seriously.

Hanson said a detective has been assigned onto the case, but no leads have currently been found.

The investigation could range from "a couple of days to a couple of months," he said, encouraging anyone with information to contact the police department as soon as possible.

Despite the threat, Maryott-Walsh said she still felt the transit system is a "safe" mode of city transportation.

"In terms of the bus threat, it was an unfortunate incident," she said.