Over 50 people were killed Sunday by Syrian security forces,a day after U.N. Secretary General BanKi-moon expressed his concern over the rising violence. On Sunday morning Syrian troops and tanks stormed the city of Deir Ezzor killing at least 38 people. In a separate military assault on a town north of Homs, activists said at least 13 people were killed by Syrian security forces. An opposition activist said loud explosions were heard in anumber of neighborhoods in Deir Ezzor after troops entered the city located in northeastern Syria early Sunday morning. The ongoing military crackdown on anti-government protestscame a day after the U.N. leader told President Bashar Assad in a telephone conversation to immediately halt the use of force on civilians. The Turkish daily Sunday's Zamman said Foreign MinisterAhmet Davutoglu plans to visit Syria and convey a stern message to the authorities there.