BBC News with Neil Nunes.

President Obama has paid tribute to the people of Boston at a memorial service for victims of the bomb attacks at the city's marathon on Monday. At an interfaith gathering at the Holy Cross Cathedral, Mr. Obama said the bombs could not beat Boston or America. To applause, he warned the perpetrators: "We will find you, and you will face justice." And he had this message for those who had been injured. "As you begin this long journey of recovery, your city is with you. Your commonwealth is with you. Your country is with you. We will all be with you as you learn to stand, and walk, and yes run again. Of that I have no doubt. You will run again." Three people died and more than 170 were wounded in the blasts.

Prosecutors in the United States have charged a man suspected of sending letters believed to contain the deadly poison ricin to President Obama. Paul Kevin Curtis from Mississippi is accused of threatening the President and the senator. He denies the charges.

A search and rescue effort is continuing in the American state of Texas after a huge explosion at a

fertilizer

plant on Wednesday night, killed up to 15 people and injured hundreds. Many buildings in the town of West were flattened by the blast which('s) registered as a small earthquake. The governor of Texas Rick Perry welcomed the offer of the federal government's full support. "President Obama called from Air Force I as he was en

route