LONDON -- British police filed their first charges in the London terror investigations Wednesday, accusing a 23-year-old man of withholding information about the July 21 transit bombers.
Police say that in the week after the attack, Ismael Abdurahman of southeast London had information he knew might help police capture suspects involved in "the commission, preparation or instigation of an act of terrorism."
Abdurahman was charged under anti-terrorism legislation and is to attend a hearing in London today.
The charges could mark an important step forward for police seeking to build cases against the 17 people in custody in connection with the July 21 assault, in which bombs planted on three subways and a bus failed to fully detonate.
Police also are trying to uncover the larger network that may have supported those attackers, who struck exactly two weeks after four suicide bombers -- also on three trains and a bus -- killed 52 victims on July 7.
One of the suspected July 21 bombers, Hamdi Issac, has been charged in Italy with association with the aim of international terrorism. Britain is seeking to extradite him.
Italy also has two of Issac's brothers in custody, and Britain is holding 14 suspects.
Italian prosecutor Pietro Saviotti said Issac's extradition could be delayed by some weeks because local authorities were looking into possible crimes committed in Italy. But he dismissed suggestions that it would block the transfer.
"I would not say we are talking about days, but about weeks" before Issac can be extradited, Saviotti said.
No suspects are being detained in connection with the July 7 attacks.
Police pursued international links Wednesday -- to Pakistan, Saudi Arabia and Zambia -- as they hunted for possible conspirators in the bombings and tried to determine whether the two sets of attackers were linked.
Zambia announced it was deporting Haroon Rashid Aswat, a British citizen of Indian descent, to Britain, and President Levy Mwanawasa said he was an alleged terrorist. However, it was unclear whether Britain suspected him of involvement in the London bombings.
British newspaper reports, citing security sources, have said in recent days that investigators don't believe he was linked to the London attacks. But Zambian authorities have questioned him about 20 phone conversations he reportedly had with some of the suspected bombers.
News reports have said suspects in both attacks worshipped at the Finsbury Park Mosque in north London, known as a hotbed for Islamic radicals. They may have gone whitewater rafting in Wales weeks before the attacks, although The Times newspaper reported Wednesday that investigators had discounted the possibility.
Also, a Pakistani official said authorities there were trying to determine whether Ethiopian-born Muktar Said Ibrahim, a suspect in and possible ringleader of the July 21 attacks, may have been in Pakistan at the same time as two of the suspected July 7 attackers.
"Our immigration officials are checking whether he arrived here," said the official, who declined to be identified because he is not authorized to speak about the investigation.
Investigators believe that any confirmation of a visit by Ibrahim to Pakistan would strengthen the theory of a link between the two groups. London's Metropolitan Police declined to comment.
Pakistan's Education Minister Javed Ashraf Qazi said there was no evidence that any of the London suicide bombers visited religious schools in Pakistan.
Police have also been pursuing a possible Saudi connection. The Sunday Times newspaper said Ibrahim took a month-long trip to Saudi Arabia in 2003, telling friends he was to undergo training there.
British investigators told their Italian counterparts that Issac made a call to Saudi Arabia before his arrest in Rome, according to Italy's anti-terror police chief Carlo De Stefano. Issac apparently was trying to get a number for one of his brothers, De Stefano said.
Many have questioned how Issac was able to slip out of Britain on the Eurostar train from London's Waterloo Station.
Sky News reported Wednesday that one of its journalists had traveled by train from London to Paris using a colleague's passport. The Home Office declined to comment on the report directly but said it was working closely with police on checks of those leaving the country.
In Zambia, Aswat told investigators he used to be a bodyguard for al-Qaida chief Osama bin Laden, according to a Zambian official who spoke on condition of anonymity because he was not authorized to communicate with journalists.
A Metropolitan Police spokeswoman declined to comment on whether Aswat -- from the same town in northern England as one of the bomb suspects -- was wanted in the July 7 attacks. The Foreign Office said only that British consular officials in Zambia were seeking a meeting with a Briton detained there.
The United States also reportedly wants to question Aswat about possible links to a plan to establish a terrorist training camp in Oregon.