Officers say they want information on Khalid Masood's "associates and places he visited".
Police name fourth victim as Leslie Rhodes, 75, and say "significant arrests" have been made.
Germanwings crash victims' families criticise the pilot's father for seeking to exonerate his son.
The president demands a make-or-break vote on a new health care bill to replace Obamacare.
It is the first time Egypt's ex-president is allowed to go home since his 2011 overthrow.
The singer writes about his Comic Relief visit and why he'll never forget the children he met.
EU Commission President Juncker admits all is not well in the EU as UK prepares to trigger exit talks.
Ancient buildings left in ruins by Islamic State militants in Syria.
Belgian prosecutors bring an attempted terrorism charge against man who drove at a crowd in Antwerp.
It sank in one of South Korea's deadliest disasters in 2014.
The far-right presidential candidate meets Russian MPs just weeks before France's elections.
British scientists say they now isolate different strains and so diagnose sufferers within days.
A sheepdog that went missing 12 days ago is rescued from a gorge where it was spotted from a train passing on a nearby railway line.
A 70-year-old says attackers "did him a favour" as assault led to his cancer being discovered.
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Lewis Hamilton puts in a scintillating performance to set the pace in second practice at the season-opening Australian Grand Prix.
The full cast are back for Red Nose Day...Actually!