(VOV) - The latest information from US investigators reveals that the Boston Marathon bombs were detonated by pressure cookers, not by mobile phones.

Bomb explosions at the finish line of Boston marathon                           ( Source: Reuters)

Initial tests showed no presence of C-4 or other high-grade explosives, suggesting that the packages detonated in the attack were crude explosive devices. The bombs killed 3 people including an 8-year-old boy and injured at least 180 others. At a press conference after meeting with national security officials on Tuesday, President Barack Obama said investigators have not confirmed the bombs were carried out by a terrorist group or a discontented person. FBI Special Agent, Rick DesLauriers, said: "This is a world wide investigation. We will search for everywhere for the perpetrators who will be responsible for that coward acts and bring them to justice".

Security forces in the US are on high alert. New York Mayor, Michael Bloomberg said the city’s security is on the highest alert until specific information about the explosions is known.

In another development, the Taliban group in Pakistan who masterminded  the failed bomb attacks in New York City’s Time Square in 2010 refused to acknowledge involvement in the bomb blasts in Boston. But a Taliban spokesperson that they still target the US and its allies anywhere in the world.

The world community strongly condemned the bomb attacks in Boston.  NATO Secretary General Anders Fogh Rasmussen said he was shocked at the news and sent his condolences to the victims’ families. Pope Francis called the attack a crazy disaster and expressed his hope that people in Boston will unite to overcome this dark time. Russia, China, Germany, France, Iran, Afghanistan, Singapore, and Turkey all strongly condemned the attack and expressed their solidarity with the American people.

Nhat Quynh – VOV correspondent in Washington