Six people have been taken into police custody in connection with the Bangladesh building which collapsed on Wednesday, killing at least 359 people. Meanwhile, hope is fading for saving survivors beneath the increasingly unstable rubble.
A martial arts instructor identified as James Everett Dutschke was charged on Saturday with possession of the biological agent ricin and attempting to use it as a weapon, after he was arrested at his home in Tupelo, Mississippi.
Two factory bosses and two engineers associated with a Bangladesh building that collapsed earlier this week were arrested on Saturday, amid protests by angry workers as the death toll from the tragedy climbed to 352.
With both suspects in the Boston Marathon bombing now dead or in serious condition at a local hospital, investigators turned their attention on Sunday to uncovering a motive for the attack as they sought to establish whether others were involved.
Pakistani police placed former president Pervez Musharraf under house arrest at his home on the outskirts of the capital Islamabad on Friday where he will remain for the next two days ahead of a hearing over allegations he committed treason.
The US Federal Bureau of Investigation released on Thursday photos and videos of two men described as suspects in its investigation into the Boston Marathon bombings, in which three people were killed and over 170 injured.
US President Barack Obama has spoken at a memorial service in Boston on Thursday, following the twin bomb attack that targeted the marathon there Monday in which three people were killed and over 170 injured.
A Mississippi man, believed to be responsible for sending the letters containing the deadly poison ricin to US President Barack Obama and Republican Senator Roger Wicker, was arrested by the FBI at his home on Wednesday.
Three men have been arrested in the south of France on suspicion of conspiring to commit terrorist activity. A police raid in a house in Marignane, close to Marseille, found a number of weapons and explosives. Neighbours say a black jihadist flag had been flying from the roof of the house. It comes a year after Islamist extremist Mohammed Merah killed 7 people, five outside a Jewish school in the south of France; French authorities fear more attacks are being planned on French soil.
French police arrested at least four people in the Paris region on Tuesday as part of an investigation into Islamic extremism in the country and abroad. It is believed they planned to travel from France to join militant groups in the Sahel.