A man was detained in Azerbaijan today in connection with the killing of 12 students and staff at a college by a gunman who then killed himself.
The motive for yesterday's attack at Baku's prestigious Oil Academy, in which most of the victims were shot in the head, remains unknown.
The general prosecutor's office in the mainly Muslim but secular state said police had detained a friend of the gunman originally from the same region in neighbouring Georgia.
Mourners laid red carnations at the university, where the attack sent shockwaves through the tightly-run former Soviet republic, a supplier of oil and gas to Europe from the Caspian Sea.
Initial accounts suggesting there was more than one gunman, and continued conflicting reports over the number of dead, is fuelling unease in Baku, where rumours ran rife as news of the shooting broke.
The gunman was identified as a 29-year-old Georgian citizen of Azeri origin, described as a loner by local media who had left his family in Russia to look for work in Baku.
Police and witnesses said he climbed from the first floor to the sixth, shooting at anyone he met. Thirteen people were wounded, of which several were reported to be in critical condition with gunshot wounds to the head.
"It's still impossible to determine whether this was the action of a psychologically unbalanced man, or a premeditated terrorist act," said opposition leader Ali Kerimli.
Students who witnessed the rampage spoke of two attackers, but the Interior Ministry and general prosecutor named only one.
A senior aide to President Ilham Aliyev has said he did not believe there was any political motive behind the shooting.
Police said the death toll today remained 13, including the gunman himself. Azeri ANS television reported that 17 had died.
Reuters