ABC NEWS reports:

As senior intelligence and law enforcement officials met again today in the White House Situation Room to deal with the “summer terror threat,” a top terror commander said an attack was coming that would dwarf the failed bombings in London and Glasgow.

Taliban military commander Mansour Dadullah, in an interview broadcast on ABC News’ “World News With Charles Gibson,” said the London attacks were “not enough” and that bigger attacks were coming.

“You will, God willing, be witness to more attacks,” he told a Pakistani journalist in an interview conducted just four days ago.

The same news agency also is reporting on the possibility of Zawahiri’s latest tape containing the signal for an attack.

Fearing a possible coded signal to attack, U.S. intelligence and law enforcement officials are studying an unusual pattern of words in the latest audiotape from al Qaeda’s No. 2 man, Ayman al Zawahri.

On the tape, posted on the Internet Wednesday, Zawahri repeats one phrase three times at the end of his message.

Have I not conveyed? Oh God be my witness.

Have I not conveyed? Oh God be my witness.

Have I not conveyed? Oh God be my witness.

A new FBI analysis of al Qaeda messages, obtained by the Blotter on ABCNews.com, warns that “continued messages that convey their strategic intent to strike the U.S. homeland and U.S. interests worldwide should not be discounted as merely deceptive noise.”

Intelligence analysts are also investigating technical clues that Zawahri’s most recent audio message was phoned in via computer phone, using voice over Internet Protocol, or VoIP.