A trail of blood led to accused Boston Marathon bomber Dzhokhar Tsarnaev as he hid inside a boat after eluding one of the biggest manhunts ever staged in the United States.
The FBI released pictures and video on Thursday of two men suspected of planting the Boston marathon bombs, appealing for help to identify the pair who were carrying large backpacks.
A letter addressed to President Barack Obama tested positive for ricin, and authorities arrested a suspect, stoking alarm in Washington on Wednesday after an earlier scare over poisoned mail.
Top-flight sport made an emotional return to Boston on Wednesday as the NHL's Bruins paid tribute to the heroes and victims of the twin bombing that killed three in the US city.
The deadly explosives detonated at the Boston Marathon were homemade devices full of nails and metal fragments, possibly packed into kitchen pressure cookers.
A parcel bomb was sent to the offices of Italian newspaper La Stampa on Tuesday but failed to detonate when opened, prompting an evacuation of the building as bomb disposal teams were deployed.
A roadside bomb in Afghanistan exploded under a bus on Monday, killing nine people and wounding at least 22 in an attack by suspected Taliban militants.
A large suicide bomb exploded near the defence ministry in central Kabul during a visit to the Afghan capital on Saturday by new US Defense Secretary Chuck Hagel.
The United States and China will on Thursday seek to tighten the UN sanctions screws on North Korea after its widely condemned nuclear bomb test last month.
Pakistan's largest city Karachi shut down on Monday to mourn 45 people killed by a car bomb in a Shiite Muslim neighbourhood, the latest in a series of devastating attacks as Pakistan prepares for elections.
India hunted Friday for perpetrators of twin bomb attacks that killed 14 people and wounded dozens more near a cinema and a bus stand in a busy neighbourhood in the city of Hyderabad.
Thousands of women refused Monday to bury victims of a bloody bombing and a strike shut down Pakistan's biggest city Karachi as protesters across the country demanded protection for Shiite Muslims.
Iran on Tuesday scorned as a "laughing matter" comments by Israeli Prime Minister Benjamin Netanyahu that Tehran is moving closer to making a nuclear bomb.
Islamist gunmen attacked the largest city in northern Mali on Sunday following two straight days of suicide bombings, intensifying their insurgency on territory reclaimed by French-led forces.