Updated

Online calling service Skype is confirming a bug that has caused instant messages to be sent to the wrong contacts.

Skype, which is owned by Microsoft Corp., said in a statement Monday that only a "small number of users" are affected. It called the bug a "rare occurrence" but did not go into details about what caused it or exactly how many people were affected.

Skype says it will send out a software update that fixes the problem in the next few days.

The bug was first described in Skype's online support forums and reported in various technology blogs.