KHARTOUM - A Sudanese Christian convert who was released from death row on Monday was detained as she and her family sought to fly out of the capital on Tuesday, her lawyer and the US State Department said.Mariam Yahya Ibrahim, 27, was detained with her American husband and their two children as they tried to board a flight at Khartoum airport earlier on Tuesday. It was unclear where they were heading, but two diplomats said they suspected that the family was trying to go to the United States via Cairo or Juba, South Sudan.Ibrahim was freed on Monday by an appeals court, which cancelled the death sentence imposed on her for having converted to Christianity from Islam, after the government came under what it called unprecedented pressure.Her lawyer, Mohaned Mostafa, told Reuters that he was with her at the police station, that she had been re-arrested, and that the police wanted to question her about providing forged information. He was unable to immediately provide more details.In Washington, the US State Department offered a different version of events, saying the Sudanese government had told the United States that Ibrahim had been detained for several hours and then released but that she had not been arrested."The State Department has been informed by the Sudanese government that the family was temporarily detained at the airport for several hours by the government for questioning over issues related to their travel and I think travel documents. They have not been arrested," State Department spokeswoman Marie Harf told reporters."The government has assured us of their safety," Harf added, saying that the US embassy was "highly involved" in working with the family and the government to resolve the matter. "We are engaging directly with Sudanese officials to secure their safe and swift departure from Sudan."The United States has imposed economic sanctions on Sudan since 1997 over alleged human rights violations. It intensified sanctions in 2006 over Khartoum's actions in its conflict with rebels in the western region of Darfur.After her release on Monday, Ibrahim was sent to a secret location for her protection after her family reported receiving threats, another one of her lawyers had said.