BRITAIN'S most senior police chief revealed yesterday that there had been a 75% increase in the number of anti-terrorism operations carried out by Scotland Yard since the London bombings.

Metropolitan Police Commissioner Sir Ian Blair's counter-terrorism officers are now receiving high-grade intelligence reports on a daily, rather than monthly, basis in the wake of the July 7 attacks, he said.

Sir Ian warned the threat was intensifying and said three further conspiracies had been thwarted since July.

There were terrorists currently in the UK who were plotting to carry out mass atrocities, he said.

The Commissioner was speaking at a conference in Westminster, central London, on policing the terrorist threat.

The event, entitled Together Against Terror, is being held by the Metropolitan Police Authority.

Relatives of some victims of the London bombings were also attending.

The bombings were carried out by four men - all with West Yorkshire links. They included Jermaine Lindsay, who was brought up in Rawthorpe, and Mohammed Sidique Khan, who lived with his wife and family in Thornhill Lees.

Khan was the ringleader of the suicide squad.

Addressing the nature of the terrorist threat since July 7, Sir Ian said: "Since then we have had an increase of 75% in the operations we are carrying out.

"We are now further flat-out than we could have ever imagined ourselves to be."

Referring to high-grade intelligence reports, he added: "My colleague, Andy Hayman (Assistant Commissioner, Specialist Operations), would expect to get, before July, maybe one of these intelligence reports arriving every month. Now we are seeing them almost daily.

"There are people in the UK as we speak who are planning mass atrocities and who will use suicide as a weapon. That is a different place to where we have been in my lifetime and in my service."

He added: "What matters is that the terrorists are here. They are going to go on trying to kill people like you and people like me.

"We have to find the right methodology, community relationships and legislative framework to defeat them."

One Metropolitan Police Authority member who has been given a briefing about the level of the current terrorist threat described it as "chilling".

Jenny Jones told delegates at the conference: "If you knew what we knew you would really be scared."

Sir John Gieve, Permanent Secretary at the Home Office, added that there was "no doubt" that Britain remained a target for al Qaida and its associated movements.