(CNN) -- For the second time in a week, Comcast customers found themselves offline -- this time, in the Midwest.
On Sunday evening, internet service outages affected Illinois, Minnesota, Indiana and Michigan, according to a Twitter account for Comcast customer service.
"I apologize for the down time," representative Bill Gerth said via Twitter late Sunday, adding that crews were working as quickly as possible to resolve the domain name system outage.
At about 1 a.m. ET Monday, Gerth tweeted, "Everyone should be just about back online, if not should be very shortly."
Last weekend, customers on the East Coast also experienced outages. The disruption affected the Boston and Washington, D.C., areas, a Comcast spokesman said. The outage came on the eve of Cyber Monday, the annual online equivalent of Black Friday when internet retailers roll out their bargains for holiday shoppers.
CNN's Jason Kessler contributed to this report.