Hamas security forces have captured members of the Palestinian militant group Army of Islam, who are thought to be holding abducted BBC correspondent Alan Johnston.
A statement released by the Hamas interior ministry said: "The arrests were carried out after all negotiation attempts... failed to free the abducted journalist."
It added: "The arrests are targeting figures who were involved in the abduction of the journalist."
The development comes as the BBC prepares to hold a rally marking the 16th week since his abduction took place in Gaze on 12 March.
It has been reported that Khattab al-Maqdisi, a spokesman of the Army of Islam group, is among those being held.
A Hamas spokesperson has said that al-Maqdisi was injured and captured after he opened fire on security forces in Gaza City.
The news following the recent release of a video showing Alan Johnston wearing what he describes as an explosive vest.
In the video, which was released by the kidnappers on the internet, Johnston says: "The situation now is very serious. As you can see I have been dressed in what is an explosive belt, which the kidnappers say will be detonated if there was any attempt to storm this area."
He added: "Captors tell me that very promising negotiations were ruined when the Hamas movement and the British Government decided to press for a military solution to this kidnapping."
Hamas has threatened to "use all means to secure" the freedom of Alan Johnston.
