Ministers from the six largest European Union countries have agreed to work together to make the internet a "more hostile" place for terrorists.
Mr Reid called people smuggling an "affront" to civilisation
Home Secretary John Reid said they would seek to crack down on people using the web to share information on explosives or spread propaganda.
The ministers also pledged to fight international VAT fraud, following a meeting near Stratford-upon-Avon.
This cost the UK £3bn a year, some of which funded terrorism, Mr Reid said.
He said the interior ministers wanted to use the internet and other media to target young audiences with messages from "secular Muslim" role models, rather than those believing in radical ideologies.
Mr Reid was speaking after a two-day summit with interior ministers from Germany, France, Spain, Italy, Poland and the UK - known collectively as the G6.
He said police would try to "pre-empt the next attack and attempted attack" by terrorists.
There would be a "continuing struggle where the terrorists try to get ahead of us and we try to get ahead of them".
The ministers were addressed by the head of Britain's security service MI5.
Mr Reid said the terrorism threat came "particularly from those who would through a perverted use of Islam constitute a terrorist threat".
However, he added that "the enemy is terrorism; the enemy is not Islam".
The ministers discussed how to encourage dialogue with Muslim communities.
Using the example of August's alleged plot to blow up transatlantic flights, Mr Reid said greater international co-operation was vital to preventing further attacks.
The meeting was aimed at sharing ideas and "best practice" rather than taking concrete decisions, a spokesman added.
Paymaster General Dawn Primarolo also briefed the ministers on the efforts of the Treasury and HM Revenue and Customs to clamp down on so-called "carousel" VAT fraud.
A Home Office spokesman said the gangs carrying out this type of fraud were "well-organised, well-resourced, innovative and known to be involved in wider criminality".
In a carousel fraud, goods - usually small, high-value items such as mobile phones and computer chips - are imported into a country and VAT is charged when they are sold.
But the importer pockets the VAT and vanishes without making the payment due to the Treasury.
The goods can then be re-exported, at which point HM Revenue and Customs pays the exporter a VAT rebate.
In the worst cases, the whole chain is crooked and the goods are repeatedly imported and exported, hence the "carousel" term.
Mr Reid also said, after the summit, that all EU members would continue to set their own immigration policies but would "interact" more.
He said people-smuggling, often for prostitution or enforced labour, was an "affront to civilisation".
The G6 group has no formal decision-making powers and is not an official body of the EU.
But it can make agreements on cross-border co-operation without needing EU approval.
The Liberal Democrat spokeswoman in the European Parliament, Baroness Ludford, said she was concerned at the way the G6 countries exerted their influence over the rest of the EU.
She said while policy discussions were needed, "what is not desirable is that the rest of the EU should be bounced into what could become legislative conclusions and decisions without having a say in that - and indeed with no parliament, either national or European, having a look in either".
It represents three-quarters of the EU's population and was established in 2003 - initially as G5 before Poland joined. It meets two to three times a year.