LONDON (Reuters) - British police on Monday said they had arrested a man who tried to climb a wall at Queen Elizabeth’s Buckingham Palace home in central London, but said that the incident was not terrorism-related.

The 24-year-old man was arrested on suspicion of trespass on Sunday evening, three minutes after he stepped over a low outer perimeter fence near the palace, the Metropolitan Police said.

“The man was not found in possession of any offensive weapons and the incident is not being treated as terrorist related,” police said in a statement.

He has been released on conditional bail and has undergone a mental health assessment.

British police are on high alert after five attacks blamed on terrorism this year. In August, a man wielding a sword outside the palace was charged under terrorism laws. Three police officers suffered minor injuries detaining him.

A number of people have tried to get into the palace grounds in recent years. A woman was arrested in October for attempting to scale the gates of the palace.

In May 2016, a man with a conviction for murder climbed over the wall and walked for about 10 minutes around the grounds of the palace before being arrested. He was jailed for four months.

Four years ago, a man armed with a knife tried to enter through a gate and was later jailed for 16 months. A month earlier, two men were arrested following a break-in at the palace.

One of the biggest security breaches at Buckingham Palace happened in 1982 when an intruder, Michael Fagan, climbed a wall and wandered into a room where the queen was in bed.