UK woman arrested over suspected terror offenses March 15, 2012 -- Updated 1741 GMT (0141 HKT) A 40-year-old woman was arrested Thursday in south London on suspicion of terror offenses, the Metropolitan Police said. NEW: A 20-year-old Moroccan man was arrested in Italy in an alleged plot, police say The 40-year-old UK woman is being questioned at a London police station Her arrest is in connection with the alleged posting of extremist material online, police say UK officers are working with their Italian counterparts over possible ties to the arrest in Italy London (CNN) -- A 40-year-old woman was arrested Thursday in south London on suspicion of terror offenses, the Metropolitan Police said. She was detained in the early hours by counterterrorism officers and taken to a police station for questioning, a police statement said. A home is also being searched. Her arrest is in connection with the alleged posting of extremist material on the Internet, the statement said. "We are liaising with the Italian authorities to establish whether there is any link to an arrest they made earlier this morning," the statement added. Italian police said they had arrested a 20-year-old Moroccan-born man early Thursday in northern Italy on suspicion of planning an attack on a synagogue in Milan. Claudio Galzerano, head of the anti-terrorist unit of the Italian police, told CNN in a phone interview that the suspect, named Jarmoune Mohamed, had been detained in the city of Brescia. He is a Moroccan citizen but has lived in Italy since he was 6 years old, Galzerano said. Police found detailed plans of the synagogue on Via della Guastella in Milan on Mohamed's computer as well as information on the security measures at the site, he said. He described the operation as an "important preventive operation" but also said there was "a very high risk" that the planned attack might be carried out. Galzerano said the suspect had allegedly createdsecret discussion groups on social networks such as Facebook in which he discussed making explosive devices. Mohamed's activities had led police to place him under 24-hour surveillance, he said. Italian investigators are working with police in the United Kingdom and elsewhere in connection with the case, Galzerano said. Italian Interior Minister Anna Maria Cancellieri said in a statement that she was "particularly glad that the operation was conducted thanks to the information from our intelligence office and foreign intelligence." CNN's Livia Borghese and Bharati Naik contributed to this report.