A suicide car bomber killed a civilian and wounded 25 Egyptian policemen when he tried to ram his car into a police barracks in the city of al-Arish on Tuesday, security sources said, the latest in a string of attacks in the Sinai peninsula.
The violence comes days ahead of an investment conference in the resort of Sharm el-Sheikh, 340 km (210 miles) south of al-Arish, that Egypt hopes will project an image of stability and attract billions of dollars.
Previous attacks have been concentrated in North Sinai.
The security sources said police were able to stop the suicide bomber from entering the barracks. Security and medical sources said a civilian was in the area by coincidence when the bomber struck.
There was no immediate claim of responsibility.
But Islamist militants based in the Sinai have carried out similar attacks that have killed hundreds of soldiers and police since the army toppled Islamist president Mohamed Mursi in 2013 after mass protests against his rule.
On Monday, a roadside bomb killed three Egyptian soldiers in Sinai, a largely lawless area bordering Israel and the Gaza Strip which is home to Egypt's most dangerous Islamist group, Sinai Province.
Formerly known as Ansar Bayt al-Maqdis, the group has pledged allegiance to Islamic State, the ultra-hardline Sunni group which controls large parts of Iraq and Syria.