Millions of callers jammed telephone lines across the United States yesterday after devastating aircraft attacks in New York, Washington and Pittsburgh, but despite the clogged lines the US national telephone networks continued to operate.

With phone lines jammed, scores of Americans turned to the internet to e-mail friends and relatives alerting them that they are all-right. "We're experiencing double call volume of a normal busy day, which is generating network congestion. There's just too many calls," said Mr Dave Johnson, a spokesman for AT&T Corp. the nation's biggest long-distance carrier.