Ljungberg, who has never managed at senior level, but was in charge of the club's U23 last season before being promoted to first team assistant in the summer, has been placed in charge while the search for a new manager is carried out.
“However long I oversee Arsenal for I will give everything I have to put smiles on faces again," Ljungberg tweeted.
“We have a busy few weeks ahead and the team needs your support. Let's get to work!"
Significantly, the Swede did not mention Emery in his post.