Police will today continue searching an area in WA's South West where two packages of explosive material were found last week.

Officers spent parts of the weekend patrolling near the Leschenault Estuary.

Testing has confirmed one of the packages contained the highly volatile explosive TATP.

It is believed the other package found nearby contained the same substance.

Both were safely detonated to remove any danger posed by the explosive which has been used in terrorist attacks, including the London bombings and a thwarted attempted by shoe bomber Richard Reid.

Police say they do not have any information to suggest there are more dangerous materials in the area.

They are asking anyone with information about suspicious chemical sales or recent activity around the estuary to contact them.