Suicide Bomber in Tehran?

A blast at a Khomeini shrine, according to Reuters:

TEHRAN (Reuters) - A suicide bomber blew himself up near the shrine of Iran’s revolutionary founder, Ayatollah Ruhollah Khomeini, in Tehran on Saturday, Iran’s semi-official Mehr news agency reported.

“A few minutes ago a suicide bomber blew himself up at the shrine,” Mehr quoted a police official, Hossein Sajedinia, as saying.

Two other people were wounded in the incident in the northern wing of the shrine, another news agency, Fars, said.

I think some skepticism is in order about who’s behind this incident.