Story highlights A 22-year-old woman is arrested in east London, police say

Six others are arrested Thursday as part of the same investigation by London police

The arrests are not connected to the Olympic Games, police say

Britain is on a heightened state of alert ahead of the Olympics, which start in three weeks

British authorities arrested a 22-year-old woman Saturday on suspicion of terror offenses amid heightened security before the London Olympics.

She is the seventh person detained in connection with an investigation by the London Metropolitan Police's Counter Terrorism Command.

The operation in London is not linked to the Olympic and Paralympic Games, police have said.

However, security is a central concern for UK authorities and the organizers of the Olympic Games, which start in three weeks, and police and intelligence agencies have stepped up monitoring efforts.

The woman detained Saturday morning in Hackney is undergoing questioning in south east London, police said. She was arrested on suspicion of the commission, preparation or instigation of acts of terrorism.

Six other suspects -- five men and a woman ages 18 to 30 -- were all arrested Thursday, also on suspicion of the commission, preparation or instigation of acts of terrorism, police said.

Officers searched homes in east, west and north London, as well as business premises in east London.

One of the men arrested had worked from 2007 to 2009 as a police community support officer for the Met Police, the force said in a statement, and "was not deployed in a specialist or sensitive role." Police community support officers are members of staff who work alongside the regular police force, mostly to tackle local anti-social behavior and low level issues.

Also on Thursday, armed police in Staffordshire closed a major highway and called in bomb disposal squads when a passenger on a bus raised the alarm over smoke coming from a fellow traveler's bag. The source turned out to be a quit-smoking aid, and no arrests were made.

Seven men were also arrested this week in the West Midlands and West Yorkshire on suspicion of terror offenses after firearms were found in a car stopped by police, West Midlands police said Friday.

It is understood that the individuals arrested in the West Midlands and West Yorkshire were not targeting the Olympics, nor did they have any links to those arrested Thursday in London.

Following the arrests, the UK Home Office website has not changed the terror threat level from "substantial," which is the third highest of five levels. The next level up is "severe," which means an attack is "highly likely," and the highest is "critical," meaning an attack is "expected imminently."

Additional security measures will be in place in London and elsewhere during the Olympics, which start in three weeks.