KHARTOUM (Reuters) - Internet and mobile services appeared to be disrupted in Sudan on Thursday ahead of the latest round of planned protests against a military takeover that upended a transition towards elections.

       Some bridges between the capital Khartoum and its sister cities of Bahri and Omdurman were also closed ahead of the demonstrations.

       Protesters said they would try to reach Khartoum's presidential palace as they try to keep up pressure on the military, which halted a power-sharing arrangement negotiated after the 2019 overthrow of Omar al-Bashir when it staged a coup last October.

       "We will occupy the streets once more, heading for the tyrant's palace, rejecting military rule, and adhering to peacefulness, our strongest weapon," said a statement from resistance committees organising protests from Bahri.

       Crackdowns on protests since the coup have left at least 57 people dead and many more injured, according to medics aligned with the protest movement.

       Calls and mobile internet services were disrupted from late morning, Reuters journalists and internet blockage observatory NetBlocks said.

       The protests come four days after Abdalla Hamdok resigned as prime minister, throwing Sudan's future deeper into uncertainty.

       Hamdok became prime minister in 2019 and oversaw major economic reforms before being deposed in the coup and returning in a failed bid to salvage the power-sharing arrangement.

       (Reporting by Yasmin Hussien; writing by Yomna Ehab; editing by Angus MacSwan)