Carolyne Phillips, from Sully, near Barry, was working in the World Trade Centre when the first plane struck.

Speaking from Manhattan last night, she said: "There are not many people around, the streets are fairly empty. People have seen some horrific things, people throwing themselves out of the top floors of buildings, other stories about people on fire. It is horrendous, just horrendous."

Ms Phillips was on the telephone to colleagues in London when she heard a "huge bang."

"The whole building shook, I dropped the phone and shrieked 'It's a bomb,' assuming that was what it was.

"I looked out of the window and saw debris flying down from above. We could not see what was happening. We had no idea a plane had gone into it at that stage, it looked like a massive explosion.

"We decided not to hang around and tried to get as far away from the scene as possible." Ms Phillips said New York City was still reeling.

"The slightest bang or noise or siren anywhere, people are cautious," she added.