An aggressive seven-hour Border Patrol sweep resulted in the arrests of more than 700 illegal aliens at the San Onofre checkpoint, officials said. A reinforced inspection staff of more than 30 Border Patrol officers checked thousands of northbound cars at the inspection point near the Orange County line on Interstate 5 on Sunday, officials said. Agents also patrolled rest stops and hills south of the station in an effort to seal off the area, officials said. The arrest total of 707 was high for the San Onofre station, where there are usually about 200 arrests on a Sunday, officials said. The operation was in response to an increase in illegal border crossings since the first of the year, said Wayne Kirkpatrick, supervisory Border Patrol agent. In the last two weeks, arrests of illegal aliens have gone up from about 700 a day in December to more than 1,250 a day, Kirkpatrick said.