The Sinai Peninsula
The Sinai PeninsulaYohanne Garon/Flash 90

A shooting at a heavily fortified security facility in a tense area of Egypt’s Sinai Peninsula on Sunday killed at least four police officers, including a senior officer, The Associated Press reported, citing two local security and health officials.

According to the officials, who spoke on condition of anonymity since they were not authorized to brief the media, at least 21 other forces were wounded in the shooting at the National Security headquarters in el-Arish, the capital city of North Sinai province.

A list of casualties obtained by The Associated Press showed that some forces suffered from gunshots and others faced breathing difficulties from tear gas fired inside the facility. The list showed that there were eight officers among the wounded.

The circumstances surrounding the shooting were not immediately clear, and there was no immediate comment from the Interior Ministry, which oversees police forces.

North Sinai is the scene of a yearslong battle against an insurgency led by Islamist militants who have carried out scores of attacks, mainly targeting security forces and Christians. In May, 16 Egyptian soldiers were killed in two separate attacks.