gr.group theory - Elements of infinite order in a profinite group

I would like to add that the restricted Burnside problem is equivalent to the fact that a finitely generated profinite group of finite exponent is finite. Now, this was of course proved by Zelmanov. But he also proved a stronger result: every finitely generated compact Hausorff torsion group is finite, see Zelʹmanov, E. I., On periodic compact groups, Israel J. Math. 77 (1992), no. 1-2, 83--95. In particular, every finitely generated torsion profinite group is finite, i.e. the Burnside problem is true for profinite groups.
BTW, Zelmanov has a more general result regarding when a pro-p group is finite (I don't remember now the exact formulation, Ignore: it should be something like all generators have finite order and the associated graded Lie algbera satisfies an identity), however, he only published a sketch of the proof which I think is in E. Zelmanov, Nil Rings and Periodic Groups, The Korean Mathematical Society Lecture Notes in Mathematics, Korean Mathematical Society, Seoul, 1992.

Edit: I was asked about this recently. So I really had to search my memory and the literature. This is what I have found: I think I read about the result in Shalev’s chapter in New Horizons in Pro-$p$ Groups (Theorem 2.1 and Corollary 2.2). However, the original reference is Zelmanov’s paper in Groups ’93 Galway St. Andrews Volume 2, LMS Lecture Note Series 212.

Here it is:
Let $G$ be a group. Write $(x_1,x_2,ldots,x_i)$ for the left normalized commutator of the elements $x_1,x_2,ldots,x_i in G$. Let $D_k$ be the subgroup of $G$ generated by $(x_1,x_2,ldots,x_i)^{p^j}$, where $ip^j geq k$ and we go over all $x_1,x_2ldots,x_i in G$. Let $L_p(G)$ be the Lie subalgebra generated by $D_1/D_2$ in the Lie algebra $oplus_{i geq 1} D_i/D_{i+1}$. We say that $G$ is Infinitesimally PI (IP) if $L_p(G)$ satisfies a polynomial identity (PI). Zelmanov proved the following theorem:

Theorem: If $G$ is a finitely generated, residually-$p$, IP, and periodic group, then $G$ is finite.

The proof is based on the following theorem for which he only sketched the proof (according to Shalev):

Theorem: Let $L$ be a Lie algebra generated by $a_1,a_2,ldots,a_m$. Suppose that $L$ is PI and every commutator in $a_1,a_2,ldots,a_m$ is ad-nilpotent. Then $L$ is nilpotent.

The question whether a torsion profinite group is of finite exponent is still open as far as I know and is considerd very difficult. (Burnside type problems seem to be very difficult.)