Pakistan has promised to intensify intelligence-sharing with Britain as part of the hunt for those behind the London [Images] bombings and warned against the assumption that there is a link between the bombers' visit to Pakistan and the terrible events.

Prime Minister Shaukat Aziz pledged to enhance intelligence sharing with UK in the hunt for London bombers, but said, "It would be simplistic to say that somebody who visits Pakistan would be prompted to do something like this."

"There is no linkage of the visits to Pakistan and these terrible events," Aziz said in an interview published in a daily on Tuesday.

Aziz's remarks followed comments by Pakistan President Pervez Musharraf [Images] reflecting widespread anxieties over suggestions that two of the three suspects of Pakistani origin involved in the bombings in London used a trip to Pakistan to prepare for the attacks.

At least one of the bombers is believed to have visited a madrassa in Pakistan. Outcry in Britain prompted the Pakistani government to renew a pledge to register these schools by the end of 2005.

• The London Blasts

Registration would force the sponsors of up to 13,000 madrassa schools to accept regular inspections by government officials and allow a broader curriculum.

The Financial Times newspaper also quoted senior Pakistan intelligence officials as saying they had almost finished questioning Pakistanis who received phone calls from Shehzad Tanweer and Mohammad Sidique Khan, two of the July 7 bombers, who visited their parents' country of origin in the past year.               

A list of telephone numbers shared by British intelligence officials with their Pakistani counterparts has been the focus of attention after suggestions that the two men may have phoned fellow militants during their visit.

"Not much concrete has come out of this effort," said a Pakistani intelligence official. "They were either family friends or personal friends, but no one who can be concretely pinned down to militancy."

Meanwhile, Pakistani officials said they were considering the possibility that Masood Azhar, head of the banned Jaish-e-Mohammed militant group, who is the subject of an intense two-week hunt, may have crossed the border to Afghanistan.

Tanweer is believed to have met members of Azhar's group during his visit to Pakistan, the report said.