\documentclass{article}

\usepackage[T2A]{fontenc}
\usepackage[russian,english]{babel}
\usepackage[utf8]{inputenc}
\usepackage{amsmath,amssymb}
\usepackage{tikz}

\begin{document}

\begin{tikzpicture}
	\node[circle,draw] (a) at (0,0) {$a$};
	\node[circle,draw] (b) at (2,2) {$b$};
	\node[circle,draw] (c) at (4,4) {$c$};
	\draw[->,ultra thick,blue] (a) -- (b) node [pos=0.5,above,red,sloped] {label};
	\draw [bend left,thick,->](b) to node[draw,fill=yellow]{1} (c);
	\draw [bend right,thick,->](b) to node[draw,fill=yellow]{2} (c);
\end{tikzpicture}

\end{document}