ST. PAUL, Minn. (AP) — Statewide turnout was expected to be low as voting in a rare August primary began Tuesday, but two competitive races to pick Minnesota congressional challengers were generating interest in the northeastern and southern parts of the state.

It’s only the second time Minnesota has held its primary election in August, since moving it up from September to give military and overseas voters more time to vote in the general election.

Secretary of State Mark Ritchie has predicted less than 15 percent of eligible voters will participate, with heightened interest in the northeastern 8th District and the southern 1st District. He said everything was going smoothly a couple hours after polls opened, but he didn’t expect to have a better handle on turnout until the end of the day.

“Everything seems to be in order and all systems are go,” Ritchie said.

Ritchie said his office mainly heard Tuesday morning from people seeking help using the state’s online polling place finder. This year’s redistricting sent many voters to new districts or changed polling places. Other people called to check whether their absentee ballots had arrived and were directed to an online absentee ballot tracking tool.

Some of the 40 legislative primaries on the ballot also could spike turnout in some areas, including three western suburban Twin Cities districts where Republican incumbents face conservative challengers.

Democratic voters in northeastern Minnesota are choosing an opponent for Republican Rep. Chip Cravaack, a conservative newcomer who upset longtime Democratic Rep. Jim Oberstar two years ago in what had been considered safe blue territory.

Former Duluth City Councilor Jeff Anderson, former state Sen. Tarryl Clark and former Rep. Rick Nolan are competing for the chance to challenge Cravaack in a race that went negative last week, with attack ads traded between Clark and the Minnesota Democratic-Farmer-Labor Party, which supports Nolan.

In the south, Republican voters were choosing between state Sen. Mike Parry and former state Rep. Allen Quist in a fight that has gotten personal. The winner will run against Democratic Rep. Tim Walz in a district that usually has been seen as competitive.

This year, Walz is seen as relatively safe after the Republicans tore into each other over over-the-top comments by each. Most recently, Parry drew condemnation after accusing Gov. Mark Dayton, a Democrat, of popping pills in a meeting.

Ritchie said election officials also are preparing for possible recounts in two statewide judicial races, where the top two vote-getters will advance to the November election. The state pays for recounts if the candidates are separated by less than one-half of one percentage point.

In northeastern Minnesota, Anderson, Clark and Nolan made a last push for votes Monday, greeting workers changing shifts at mines and mills and invading restaurants.

Last week, Clark ran a TV ad accusing Nolan of “a blatant misuse of taxpayer dollars” as head of the Minnesota World Trade Center more than two decades ago. Nolan struck back, calling the ad “gutter politics.” The Minnesota DFL came to his defense with a radio ad calling Clark “just another politician who will say or do anything to get elected” following her recent move into the district after losing to Republican Rep. Michele Bachmann two years ago.

“It’s too bad she decided that she needed to go negative,” said Nolan campaign manager Mike Misterek. “That’s just not the way we do politics up here.”

Outside groups including the DFL; Washington-based Emily’s List, which helps women candidates who support abortion rights; and Washington-based Friends of Democracy, a super PAC funded by the son of magnate George Soros, already have spent more than $520,000 on the race. Clark, a former state senator, has pulled in far more money than her primary rivals.

Clark campaign manager Joe Fox said the campaign was pushing all out to get voters to the polls.

The ad exchange between Clark and Nolan highlighted weak spots — Nolan’s age, 68, has been a potential negative because it ties him to an earlier era. Clark has been called a district-shopper after moving into a leased condo in Duluth last year.

Anderson, a former Duluth City Councilor from the Iron Range, was seen as less experienced. But campaign spokesman Nate Dybvig said the others’ attacks weren’t hurting.

“The negative advertising is really helping us a lot,” Dybvig said Monday. “People aren’t looking for that sort of stuff.”

Nolan was relying on the DFL Party’s help to turn out primary voters after getting the endorsement, campaigning in International Falls and Brainerd on Monday.

Clark, a former state senator, campaigned on the Iron Range and in Duluth, including at a picket line with striking auto dealer workers in Duluth.

Anderson campaigned on the Iron Range and in Duluth, where Duluth Mayor Don Ness and state Rep. Tom Rukavina led a rally.

Cravaack planned to kick off his campaign Wednesday with a tour of the district. He had $920,000 in the bank in late July.

In southern Minnesota, Parry, a state senator from Waseca, has been on the defensive since claiming he saw Dayton take 15 to 16 pills at a meeting. The remark came after Parry made an issue of decades-old comments Quist had made about social issues to raise questions about Quist’s electability.

Quist campaign manager Julie Quist, the candidate’s wife, said the former state representative from St. Peter stayed focused on eliminating the deficit as his key campaign issue.

Elsewhere Tuesday, U.S. Sen. Amy Klobuchar had no major competition and was expected to advance easily. Republican Kurt Bills, his party’s preferred candidate, had two challengers in his primary. The Independence Party also had a contested party between Stephen Williams and Glen Menze.