British police investigating the botched London subway attack of July 21 said Thursday they had charged two women under anti-terror laws.

Weshshiembet Girma (search), 29, and Muluemebet Girma, 21, of separate addresses in south London, were charged with failing to disclose information that could have helped police secure the arrest, prosecution or conviction of a person involved in terrorism, a Metropolitan Police spokeswoman said.

Press Association reported that the women are sisters and that both were arrested on July 27, accused of failing to disclose the required information between July 21 and July 28.

They are the second and third persons to be charged in Britain in connection with the failed July 21 bombings on London's subways.

The first person charged — Ismael Abdurahman (search), 23, from southeast London — appeared in court Thursday to face charges of withholding information that helped suspected subway bomber Hamdi Issac avoid capture.

London police are continuing to detain 12 other suspects without charge.