Identity of aircraft that mined the approaches to Holyhead port in July-August 1940?

[Sid Guttridge]

A merchant ship and two navalized fishing vessels were sunk by mines at the approaches to Holyhead port on 22 July and 16 August, 1940.
No U-boats laid mines in the Irish Sea, so it must have been an aircraft. It seems most likely that it was a Ju88.
Does anyone know what Luftwaffe unit laid these mines, what type the mines and aircraft were, and when?

Many thanks

Sid.

[Chris Goss]

It all depends on when these mines were dropped

[Nick Beale]

AFAIK most or all of the mining during the Battle of Britain was being carried out by units of the 9. Flieger Division but the Luftwaffe's daily sitreps don't go into detail, usually just referring to aircraft of the Division carrying out "special operations".

Here's one ULTRA from 5 August 1940:

At 0745 Seefliegerhorst 12/1 informed 9 Flieger Division that 50 air mines (Luftminen) type B and 40 air mines (LM) type A had arrived with escort detachment of Stabsfeldwebel Stefan. They were to be stored 1600/6/8. (A)

The “air mine advanced HQ” had not yet arrived. (C)

At 0800/5/8 Ltn. Lindner reported to Fl.Div. 9 that LM Vorkommando (air mines advanced HQ), strength 2 officers and 10 men had arrived at Brest Harbour station. (A)

NOTE: (A) and (C) are reliability ratings for Bletchely Park's interptretation of parts of the original message. (A) was the highest.