A Chicago Marathon official said Tuesday that registration for the October event will not reopen until at least Thursday after website woes caused registration to be temporarily suspended.

Fifteen thousand entries to the Oct. 13 race remain. The citywide race will be capped at 45,000 participants.

"We are incredibly sorry that runners interested in signing up for the 2013 Bank of America Chicago Marathon experienced such difficulties today. We have been working nonstop with our registration provider to find the root of the problem and a solution," marathon race director Carey Pinkowski said in a statement.

"Before we reopen registration, we need to make sure all technical issues are permanently resolved. We will provide ample notice regarding when the registration process will reopen."

The 36th annual marathon opened registration at noon Tuesday, and runners complained they had trouble signing up for the 26.2-mile event.

A marathon spokeswoman told RedEye that race registration was working earlier in the day but running slow. Officials suspended registration at about 3:30 p.m.

David Blumenthal, 30, said he spent 45 minutes of his lunchtime refreshing the registration page. He finally got through--and then he was charged twice. This will be the Lincoln Square resident's first Chicago Marathon. He described the registration process as frustrating.

Cook County Commissioner John Fritchey (D-Chicago) said it took him 50 minutes and multiple reloads of the registration page to register for the Chicago Marathon, which he called an eight-month goal.

Michael Gann of Alabama had better luck. He started trying to register at 12:40 p.m. and was able to finish the process at 12:55 p.m. Gann said this will be his fourth Chicago Marathon.

The race sold out in six days last year, a record. Registration is first come, first served. The cost to register is $175 for U.S. participants.

Runners who believe they may have been charged twice can contact the Bank of America Chicago Marathon at office@chicagomarathon.com or contact the registration provider Active.com customer service line at 877-228-4881.

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