From the BBC:

Hamas security forces in Gaza have detained members of the Palestinian militant group which claims to have abducted BBC reporter Alan Johnston.

Among the arrested was Khattab al-Maqdisi, a spokesman of the Army of Islam group, Hamas said.

"The arrests were carried out after all negotiation attempts... failed to free the abducted journalist," the Hamas-run interior ministry said in a statement.

Alan Johnston was kidnapped in Gaza on 12 March.

The BBC is holding a rally for Mr Johnston on Monday to mark the 16th week since his disappearance.

Read this post for worrisome context.