Image copyright PA Image caption Officers searched several properties including this one in Desborough Avenue, High Wycombe

Police investigating an alleged Islamist terrorism plot targeting the UK have been given seven more days to question four men arrested last week.

The men were detained in west London and High Wycombe on Thursday and Friday.

The four, aged between 19 and 27, were all taken to police stations in central London after their arrests.

Scotland Yard has refused to comment on suggestions that Remembrance Sunday was the target of any plot.

Police said a 27-year-old man was arrested in a car in a street in Southall, at 20:30 GMT on Thursday. Armed officers assisted but no shots were fired.

A 22-year-old man was arrested in Hounslow at 20:45, the same time that a 19-year-old was arrested in High Wycombe. Firearms officers assisted with both arrests.

A 25-year-old was arrested in Uxbridge at 02:55 on Friday.

They were all held on suspicion of being concerned in the commission, preparation or instigation of acts of terrorism

The Metropolitan Police said a number of homes in Hounslow, High Wycombe, Uxbridge, Southall, Greenford and Hayes were searched by specialist officers as part of the investigation.

In a statement, the force said the arrests and searches were "part of an ongoing investigation into Islamist related terrorism".