TEHRAN — Sunni insurgents in Pakistan increased attacks on Iranian border posts in the southeast of the country this week, employing methods similar to those used by Islamic State militants in Syria and Iraq.

In one instance, a car bomber struck a fortified base near the city of Saravan, killing a senior officer and prompting Iranian commanders and politicians Thursday to call upon Pakistan to control its borders. On Tuesday, three police officers were killed in an ambush after responding to a distress call.

These were only the latest in a series of attacks. Last month, insurgents rammed a vehicle laden with more than 1,000 pounds of explosives into one of the outer walls of a central base before launching a surprise attack with a convoy of pickup trucks carrying 70 insurgents, a senior military official told the Fars news agency this week.

The official, Brig. Gen. Mohammad Pakpur of the Islamic Revolutionary Guards Corps, said the attackers had been repelled only after a long firefight and the arrival of reinforcements, flown in by helicopter from other bases.