Is there any restriction on foreign trips after applying for citizenship? The trips will not be longer that 2 weeks.
As others have noted above, you are allowed to travel abroad after filing N-400.
In general, foreign trips are relevant to an N-400 application in two ways: for satisfying the physical presence requirement and for satisfying the continuous residency requirement.
The physical presence requirement only has to be satisfied at the moment of filing N-400.
Any trips taken after N-400 is filed have no effect in relation to the physical presence requirement at all.
By contrast, the continuous residency requirement has to be satisfied all the way up to the naturalization oath. So an extended foreign trip (something like several months in duration) taken after N-400 is filed may cause a problem.
However, a couple of short trips (a couple of weeks long, as you say) should be perfectly fine.
You still need to report the trips taken after filing N-400 and before the interview at the interview itself, and the trips taken after the interview at the oath.