(CNN) -- A married couple plotting a massive suicide bombing to coincide with the 10th anniversary of the London transportation system attacks were convicted Tuesday of preparing for acts of terrorism, officials said.
Mohammed Rehman, 25, and his wife, Sana Ahmed Khan, 24, were arrested in May after authorities noticed extremist posts on Rehman's Twitter account, including one that appeared to ask for advice about what sites in London to bomb.
"Westfield shopping centre or London underground? Any advice would be appreciated greatly," said one tweet, which included a link to an al Qaeda statement on the July 7, 2005, terror attacks in London that left 52 people dead and as many as 300 wounded.
Other tweets "included extremist rhetoric alongside images of homemade devices and instructional material" and authorities also found that Rehman conducted online research about ISIS, how to make explosives and the July 7 attackers, according to a statement from British counterterrorism police.
After the pair were arrested, police searched Rehman's home and found a stockpile of chemicals and bomb-making materiel, the police statement said -- purchases apparently made online and financed by Khan, who took out loans and transferred money to her husband's account.
Authorities also found video on Khan's phone of Rehman carrying out a practice explosion in his back yard in November of 2014.
"These were dangerous individuals who represented a genuine threat but through counter-terrorism policing we were able to intercept them before they could carry out their plans," said Assistant Chief Constable Laura Nicholson, head of the South East Counter Terrorism Unit and Regional Organised Crime Unit, in the police statement.
"It is clear that Rehman and Khan shared a radical and violent extremist ideology. They actively accessed extremist material on the internet and used social media to develop and share their views as they prepared acts of terrorism."
Sentencing is expected in the next few days, according to the British newspaper The Independent.