London police on Saturday charged a suspect in the failed July 21 attacks with conspiracy to murder and possession of explosives — the first charges to be laid in Britain against any of the would-be bombers.

Yassin Hassan Omar (search), 24, is suspected of trying to bomb a subway train near Warren Street station on July 21. The Metropolitan Police said he was charged with conspiring "with others unknown to murder passengers on the transport for London system."

The July 21 attacks came two weeks after suicide bombers killed 56 people on three subway trains and a bus.

Omar, who was arrested in the English city of Birmingham (search) on July 27, faces three other charges: attempted murder; making or possessing an explosive substance with intent to endanger life or cause serious injury; and conspiracy to use explosives.

Two other suspects in the failed July 21 bombings, Muktar Said Ibrahim, 27, and Ramzi Mohammed, were arrested in London on July 29. A fourth, known as Osman Hussain and Hamdi Issac, was arrested in Rome and is being held there on international terrorism charges.

In response to the bombings, Prime Minister Tony Blair (search) announced a raft of tough measures to crack down on extremist Islamic clerics.

The government defended the plans Saturday, as critics warned the measures could further alienate British Muslims.

Britain's chief legal official, Lord Chancellor Charles Falconer (search), said the deadly attacks in London on July 7 showed the government must act against people "who are encouraging young men who are becoming suicide bombers."

"I think there is a very widespread sense in the country subsequent to July 7th that things have changed. A new balance needs to be struck. It needs to be a lawful balance, but it needs to be an effective balance," he told British Broadcasting Corp. radio.

Since the bombings on three subway trains and a bus, which killed 52 people and four suspected suicide attackers, Blair's government has been trying to build support among political opponents and Muslim leaders for new anti-terrorism legislation.

On Friday, the prime minister announced proposals to deport foreign nationals who glorify acts of terror, bar radicals from entering Britain, close down mosques linked to extremism, ban certain Islamic groups and, if necessary, amend human rights laws.

But the government's new plans appear to have cracked the spirit of consensus.

Liberal Democrat leader Charles Kennedy warned that the measures could alienate the law-abiding majority of Britain's 1.8 million Muslims and inflame tensions.

"A fundamental duty, a responsibility on all of us, whether government or nongovernment, is to uphold the rule of law and the safety of the citizen," he said. "But alongside that, of course, is to uphold civil liberties and the right to free speech. It is getting that balance right that will be very important," he told BBC radio.

A British Muslim group called the Islamic Forum Europe warned the measures could jeopardize national unity in Britain.

"The measures are counterproductive and will encourage more radicalization," said forum President Musleh Faradhi. "Many Muslims will perceive our prime minister as playing into the hands of the terrorists."

He also criticized the government's plans to ban Hizb ut-Tahrir, a radical Islamic group that calls for the formation of an Islamic caliphate and is banned in several countries in Central Asia. Supporters insist it is a nonviolent group persecuted by corrupt governments.

Nasreen Nawas, a spokesman for Hizb ut-Tahrir, said Saturday that banning the group "has as its aim the curtailment of legitimate Islamic political debate."

Meanwhile, two British newspapers reported on a possible Saudi connection to the attacks.

The Sunday Telegraph and The Observer, citing unnamed Saudi security officials, said two al-Qaida operatives in the kingdom had made calls, text messages and money transfers to Britain earlier this year. The newspaper said the two men had since been killed in separate gun battles.

Police have yet to make firm links between the bombers and foreign militants.