Which part of speech is "as well as"? Is it both preposition and conjunction?

1. We have a responsibility to our community as well as to our families. --- Conjunction

2. He broke the window, as well as destroying the wall. --- Preposition
mehdi kordWhich part of speech is "as well as"? I

There are three words, so you have three parts of speech.
Some dictionaries list the phrase "as ... as" as an idiom with the central word being an adverb or adjective.