[AUCTeX] labels in align env (amsmath style)

[Seweryn Kokot]

Hello,

I'm using amsmath package in a tex file and I want that whenever I
insert align environment, a label is put automatically as in equation
environment. 

In equation I get:

\begin{equation}
  \label{eq:11}
 c = 5  
\end{equation}

but inserting align env (C-c C-e) I get:

\begin{align}
  a = &  3 + 5 \\
  b = & 4 + 6
\end{align}

instead of:

\begin{align}
  \label{eq:12}
  a = &  3 + 5 \\
  \label{eq:13}
  b = & 4 + 6
\end{align}

Should I insert labels manually or any other way? 

regards
SK