Five Sudanese security officers were killed in a clash during a raid on an ISIS-linked group in the capital Khartoum on Tuesday, a statement by the general intelligence service said.
In a statement, the agency said 11 foreign fighters "of various nationalities" were detained when security troops stormed three ISIS hideouts in the southern Khartoum suburb of Gabra.
Four foreign nationals hiding in one of the three properties escaped and were being pursued by security forces, the General Intelligence Directorate said.
It did not give the nationalities of the four men on the run or the 11 arrested by the troops. It also did not say what the terrorists were planning in Sudan or when they arrived.
Two of the five security men killed by the militants were officers, while the other three were enlisted men, the directorate said. A third officer was wounded.
All six casualties were shot at one of the three hideouts.
In June, security forces announced the arrest of nine al-Qaeda members who were plotting attacks in the country.
Sudan shares a desert border with Libya through which militants cross in both directions.
Eastern Libya is home to extremist groups. Sudan's border with Egypt, where ISIS militants have for years been battling security forces in the Sinai Peninsula, is heavily policed by the Egyptians.
Another group of ISIL fighters is active in Yemen, across the Red Sea from Sudan.