An Egyptian militant group that has waged a deadly campaign mostly against local security forces released an audio statement early Monday pledging its allegiance to the Islamic State, the extremist group fighting in Iraq and Syria. The statement, released on a Twitter account associated with the Egyptian group, Ansar Beit al-Maqdis, demonstrated the growing clout of the Islamic State, also known as ISIS or ISIL. The group has recruited jihadists from dozens of countries, including thousands of fighters from North Africa and the Persian Gulf. In the recording, which was said to come from Ansar Beit al-Maqdis’s information department, a man said the group promised to “obey” the leader of the Islamic State, Abu Bakr al-Baghdadi. (News reports from Iraq said Mr. Baghdadi was wounded in airstrikes over the weekend, but there was no definitive word on his status.) The confrontation between insurgents and the Egyptian government […]