Yemeni authorities on Saturday arrested a woman suspected of sending the bombs.
Officials said the woman was detained as part of the manhunt as authorities search for a number of suspects believed to have used forged documents and ID cards that played a role in the plot that was thwarted on Friday.

Yemeni President Ali Abdullah Saleh told reporters in the capital, San’a, that the United States and the United Arab Emirates had provided him with information that helped identify the woman as a suspect. He said security forces had surrounded a house that was believed to be holding the woman.

Two security officials later said the woman had been arrested, although they did not specify where she was detained.The results of Britain’s preliminary investigation escalated the seriousness of a plot that US investigators said bore the hallmarks of al-Qaeda.

The investigators have said the mail bombs found in the United Arab Emirates and England on Friday were headed to two synagogues in Chicago.

A second package was discovered in Dubai, where white powder explosives were found in the ink cartridge of a printer, police said in a statement. The device was rigged to an electric circuit, and a mobile phone chip was hidden inside the printer, the statement said.

Both bombs contained the industrial explosive PETN, the same chemical used in the failed Christmas bombing of a Detroit-bound airliner. Al-Qaeda’s Yemen branch took responsibility for that attack.

Investigators were taking a close look at the group’s bomb making expert, Ibrahim Hassan al-Asiri, who helped make the bomb used in the Christmas attack and another PETN device used against a top Saudi counterterrorism official last year, a US intelligence official said. The Saudi official survived the blast but it killed the suicide bomber.

Yemeni authorities were checking dozens more packages in the search for the terrorists who sent the bombs, though there were no signs of additional explosives. Authorities questioned cargo workers at the airport as well as employees of the local shipping companies contracted to work with FedEx and UPS, a Yemeni security official said.

Yemen is home to the radical US-born Muslim cleric Anwar al-Awlaki. He has been linked in the Christmas attack and has inspired other terrorists with his violent message. Also hiding in Yemen is Samir Khan, an American who declared himself a traitor and helps produce al-Qaeda propaganda.