Topeka ? Problems that frustrated telephone callers in a five-state region, including Kansas, were resolved Tuesday, an SBC spokeswoman said.

But Nancy Pollock, a spokeswoman for the phone company formerly known as Southwestern Bell, could shed little light on what happened.

The problem, which began about noon Monday, caused many callers to be greeted with busy signals, no dial tone or the recording: “We’re sorry, all circuits are busy now. Will you please try your call again later?”

Landline-to-landline calls that were tried again eventually went through. But many landline-to-wireless calls simply would not connect.

By 4 a.m. Tuesday, the problem had been resolved, Pollock said.

She said the problem had been caused by “issues involving links between SBC’s network and the network of TSI.”

TSI is Telecommunications Services Inc. and provides signaling networks that enable calls to connect, she said. Apparently, some TSI links went out, and the remaining links were unable to hand the resulting call load. Workers began restoring the links about 1 a.m. Tuesday.

But what caused them to fail, Pollock said, remained a mystery. She referred calls to a TSI spokeswoman, who didn’t return a phone call from the Journal-World.

Pollock said the problems callers had were sporadic. “No one completely lost service,” she said. “We were one of several carriers that were affected.”

Other phone companies said they had been informed a large, fiber-optic line, which carries phone traffic, had been cut in Missouri. But SBC officials said that did not appear to be related to problems on the network.

In Lawrence, the police and Kansas University reported few problems with phones Monday or Tuesday. The Kansas Corporation Commission, which regulates phone service, and the Kansas Department of Administration, which oversees state government phones, also reported few complaints.

In Kansas City, Mo., however, officials with Verizon Wireless, Sprint PCS, Cingular Wireless and T-Mobile said landline calls made to their wireless customers in the Kansas City area were persistently blocked. Wireless-to-wireless calls did not appear to be affected because they did not have to connect with the SBC landline network.

Pollock said she had no idea how many telephone calls were affected.

“No one lost service. It was sort of a traffic jam on the line,” she said.

Emergency service workers in the Kansas City metropolitan area reported some phone problems, but nothing serious.