Three policemen were also killed in the attack on the Karachi corps commander Lt. Gen. Ahsan Salim Hayat.
Hayat escaped unscathed, chief army spokesman Maj. Gen. Shaukat Sultan told reporters in the capital Islamabad.
"Seven army men were among 10 people killed in the attack," Sultan later told the private Geo television station.
Hayat is the top military official in Pakistan's largest city of 14 million people, which over the past month has been rocked by anti-government attacks and sectarian unrest that has killed dozens of people.
"He is safe. He's in his office, but his guard and driver are injured," Sultan said
Military spokesman Idris Malik said that the general's vehicle had already passed by when shooting started from buildings on both sides of the road on a jeep at the end of the convoy, near the start of Karachi's Clifton Bridge.
He said five army personnel inside the jeep, which had no military markings, sustained multiple gunshot wounds. Soldiers in the convoy returned fire and the general travelled on to his office.
Abd al-Majid Dafdi, a police officer, said police found an abandoned Toyota van elsewhere in the city pocked with bullet holes that they suspect was used in the attack. There were bloodstains and an AK-47 assault rifle inside. The van had been stolen Wednesday night.
Pakistani police take up positions
after the attack on Hayat
Saif al-Rahman, who lives in one of the apartments, said he saw four men fleeing in a grey coloured car while shooting with AK-47s.
"As I came out I heard gunfire. When I looked back I saw the men driving away in the car," he said.
Witnesses said there were at least three vehicles in the general's convoy. He usually travels in a limousine in a convoy of eight or 10 vehicles.
Muhammad Husain, a police officer, said he had spotted a bag on the road after the attack and threw it onto a plot of empty land nearby, where it exploded, hurting no-one but collapsing a 3-metre high wall.
Security officials later saw another suspicious bag by the bridge which was found to have a bomb inside. It was defused.
A wave of sectarian violence in Karachi last month killed over 60 people.
In May, Karachi suffered two separate bombings at Shia Muslim mosques and the killing of a prominent cleric from the majority Sunni Muslim community.