OTTAWA - RCMP made an arrest on Parliament Hill shortly before the arrival of U.S. President Barack Obama on Thursday.

A police spokesman said the arrest was made after a young man allegedly tried to sneak past a security checkpoint.

A group of burly RCMP officers wrestled the man to the ground at Wellington Street, just in front of the Parliament Hill lawn.

The man was later turned over to Ottawa city police, who later released him without laying charges, said RCMP spokesman Sgt. Jean Hainey.

Crowds were relatively sparse on the front lawn of Parliament Hill as Air Force One touched down at the airport, about 20 minutes' drive away, though the numbers grew during the day.

The Parliament Buildings were surrounded by fencing and crowds were being kept in check by double steel barriers.

Transport Canada declared the airspace over the capital a no-fly zone for the duration of the visit. Police said there were two airspace violations Thursday, but "those instances were resolved without incident."

There were no other details.