Retirement at age 60 - civil service job

I assume you're talking about Social Security retirement benefits. The earliest you can receive Social Security retirement benefits is age 62. Receiving retirement benefits at age 62 will reduce your benefit if you retire before your "full retirement age". If you're disabled or a surviving spouse you may qualify for benefits before age 62.

See : http://www.ssa.gov/pubs/10035.html

If you work for an employer who does not withhold Social Security taxes from your salary, such as a government agency or an employer in another country, the ­pension you get based on that work may reduce your Social Security benefits.

See : http://www.ssa.gov/pubs/10045.html