KHARTOUM (Reuters) - Sudanese security forces have confiscated the Sunday editions of two newspapers, editors said, the latest in a crackdown that has hobbled the country's independent media.

Censorship was officially abolished in Sudan in 2009, but the secession of South Sudan a year ago, border tensions, and a spate of small anti-government demonstrations have worsened the situation for press freedom.

Authorities confiscated copies of the independent al-Sahafa, one of Sudan's oldest dailies, after it had been printed, the newspaper's editor Alnoor Ahmed Alnoor said.

"We consider the confiscation to be equal to an economic penalty on the newspaper," he said, adding the authorities did not give a reason for the seizure.

A security agent also went to the printing house of the al-Jarida newspaper after midnight and banned it from publishing, managing editor Idris al-Douma said. "They confiscated every copy of the paper," he said.

He too said he was not given a reason why the papers were seized.

The security agency did not issue any immediate statement. The National Press Council, which is in charge of licensing newspapers, could not be immediately reached for comment.

Sudan ranks 170th of 179th in a global press freedom index compiled by Reporters Without Borders, a media watchdog.

The Arab-African country has been facing an economic crisis since South Sudan broke away more than a year ago under a 2005 peace deal, taking with it about three quarters of the country's economically vital oil production.

The situation was worsened when the landlocked South shut down its entire output in January in a dispute with Khartoum over how much it should pay to export through the north.

Tough austerity measures announced in June to plug a budget gap sparked a series of anti-government demonstrations, but the protests have mostly petered out since then under a heavy security crackdown.

Sudan and South Sudan are set to resume talks over border security that could open the way to resuming oil exports after the two struck an interim deal on fees last month.

(Reporting by Khalid Abdelaziz; Writing by Alexander Dziadosz; Editing by Alison Williams)