LONDON (REUTERS) - A British man has become the second in three days to be charged with preparing acts of terrorism and will appear at a London court on Monday, police said.

Britain raised its international threat level to the second-highest classification of "severe" in August and police chiefs say counter-terrorism operations are running at an exceptionally high pace not seen in years.

Mustakim Jaman, 23, from Portsmouth, southeast England, was charged on Sunday and is due at Westminster Magistrates' Court on Monday, Thames Valley Police said in a statement.

On Friday 26-year-old Tuhin Shahensha, also from Portsmouth, was charged with the same offence. The court heard he had intended to travel to Syria and fight in the country's civil war.

Both men were arrested by the South East Counter Terrorism Unit in a series of raids earlier this month.