More than 650,000 high school seniors and graduates in South Korea took the state-administered annual college entrance exam Thursday, the most crucial test of their academic careers seen as the deciding factor in their choice of college and future professions.

A total of 650,747 people applied to take the nine-hour standardized College Scholastic Ability Test that was administered at 1,257 test centers across the country, the education ministry said.

The exam, which consists mostly of multiple-choice questions, is divided into five sections -- Korean language, mathematics, English, social and natural sciences and a second foreign language.

The test started at 8:40 a.m. and was to run through 5 p.m., including lunch and breaks, the ministry said.

The government imposed various traffic control and anti-noise measures as part of efforts to ensure that the most crucial test in a student's academic life was executed without any glitches.

Buses and subway trains extended their rush hour services to help all exam-takers arrive at the test sites on time, the government said.

The stock markets opened for trade one hour late, while government offices and enterprises in nearby areas also opened an hour later than usual to keep the roads clear for students on their way to the test centers, according to the government.

Police operated a temporary call center for students in need of a ride offering to transport them to the test centers by patrol car or on the back of a motorcycle, it added.

Flight landings and takeoffs were banned for 40 minutes in the afternoon during a listening section of the English exam, according to the education ministry.

Test applicants were banned from carrying to their seats electronic devices, including mobile phones, digital cameras, MP3 players and electronic calculators, for concerns they might be used to cheat, the ministry said.

The education ministry will announce answers to the questions on Nov. 18 and the applicants will be individually notified of their test results by Nov. 27, it added. (Yonhap News)