Security has been tight in Boston Tuesday in the aftermath of the marathon bombings.
Heighten security caused delays for some Chicago runners flying out of Logan International Airport.
A few flights were grounded Tuesday morning when officials ordered a ground stop and a temporary flight restriction over Boston.
At least two planes were held up while passengers and their luggage removed.
One of those flights was bound for Chicago.
United Airlines Flight 636 landed at O’Hare Airport a couple of hours late.
The airline says the crew asked that customers and their bags be re-screened.
A couple of passengers were removed from the flight.
There were no reports of any arrests.