Updated

Three members of the Air Force have asked to be discharged because they are gay, moving quickly to get out of the military under the ban on openly gay service before its expected repeal later this year.

Pentagon officials said the other military services have not seen any similar effort this year under the so-called don't ask, don't tell law that prohibits gays from serving openly. Defense Secretary Robert Gates has said there are no roadblocks to ending the 17-year-old ban, but it probably won't happen until mid-summer. Gates leaves office this week.

According to the Air Force, during the past month two female staff sergeants and a male 2nd lieutenant made statements identifying themselves as gay and asked to be separated quickly from the service. Only one other person, an airman 1st class, has been discharged under the law since last October.

Air Force Secretary Michael Donley approved the discharges of the two women, and accepted the resignation of the airman who requested separation from the service. Gates issued an order last October that said no one could be discharged under the gay ban unless it was approved by the secretary of the military service involved.

The armed services are wrapping up their training of the force on the new law, passed last December that allows gays to serve openly. Before the law can go into effect, defense leaders have to certify that it will have no adverse impact on the military. So far, military leaders say they have seen no widespread resistance to the policy change.

In a survey of the troops last year, two-thirds predicted little impact on the force's ability to fight. But the greatest complaints about the change came from combat troops, including many in the Marine Corps and Army.

Gates has met with the military and civilian leaders of the services and has started to prepare for certification. But the final action will be left to the next defense secretary, Leon Panetta, who will be sworn in on Friday. The repeal would take effect 60 days after certification.

In a statement issued Monday, Alexander Nicholson, executive director of Servicemembers United, said it is shocking to see incidents of people "trying to force the Pentagon to let them out of the service obligation" because the law is still on the books.

Servicemembers United is the nation's largest organization of gay and lesbian troops and veterans.