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.