An Egyptian official said the country's border crossing with Gaza, which was closed after a deadly attack on policemen this week, has reopened.
Another official said Egyptian troops killed four militants who attacked a military checkpoint in Sinai near the border with Gaza.
Attacks in the Sinai Peninsula have increased since a military coup ousted Egypt's Islamist president Mohammed Morsi last month.
The Rafah border crossing was closed after militants ambushed and killed 25 policemen on Monday in one of the deadliest attacks in Sinai recently.
General Sami Metwali said the crossing will be open only for four hours every day because security concerns remain high in Sinai.