The identity of the young woman whose body was found on 19 September in a French town close to the border has now been confirmed.
The latest figures show that 754 new cases of coronavirus were discovered over the last 72 hours.
The grenade was located shortly after 11am on Monday in Hosingen.
The constitutional court has judged that the national Covid laws did not infringe on the country's constitution, an argument used as a line of defence by two known opponents of pandemic health measures.