Two more arrests have been made by counter-terrorism police after an alleged plan to commit arson at an unknown site connected to the Jewish community.

The Metropolitan Police said a 19-year-old man and a 26-year-old man were arrested in Watford on Tuesday and remain in police custody.

A total of nine people have been arrested over the past three days as part of the investigation. The other seven have been released on strict bail conditions, the Met said.

Assistant Commissioner Vicki Evans, senior national co-ordinator of Counter Terrorism Policing, said: "We are continuing to identify and arrest suspects who we believe were involved, or planning, the recent arson attacks in north-west London."

Police say those bailed after being previously arrested for conspiracy to commit arson include three men aged 24, 25 and 26, detained in Harpenden in Hertfordshire on Sunday evening.

A further 25‑year‑old man was arrested in Stevenage the following day.

Later, also on Monday, a 26‑year‑old man and two women, aged 50 and 59, were arrested in a car near Birmingham.

Separately, since late March, there have been a series of arson attacks across London, including Jewish community ambulances that were targeted in Golders Green, two synagogues and a former Jewish charity. Another incident involved a drone which was flown near the Israeli embassy.

An investigation into an incident in Kensington Gardens is also ongoing after jars were found containing a non‑hazardous substance on 17 April.

A 39‑year‑old man remains in custody after being arrested on Tuesday under the Terrorism Act.

Police say they have gained a warrant of further detention which allows him to be held until Tuesday 28 April.

Counter-terrorism officers have now arrested a total of 25 people in connection with these incidents.

Police say there will continue to be an increased presence of uniformed and plain‑clothes officers across north-west London following this series of incidents.

This includes patrols outside Jewish places of worship, businesses and other key community sites to deter offenders and provide reassurance.

Evans added: "My message to anyone even considering getting involved in this type of activity is this: the stakes are high and it is absolutely not worth the risk."