Two cars exploded minutes apart Wednesday outside an English-language school near the U.S. consul's residence in Karachi, killing a policeman and wounding 25 other people, officials said.

A bomb planted inside the first car detonated outside the gate of the school, called the Pakistan-American Cultural Center (search), said Ghulam Mohammed Dogar, senior superintendent of police in this southern city.

Twenty-five minutes later, a larger blast ripped through a second car parked nearby.

Wreckage from the second car flew in the air and hit bystanders. Some stumbled away with minor wounds. At least one other was carried away in a stretcher, bleeding heavily, as the second car billowed fire and smoke.

The blasts killed one policeman and wounded 25 other people — including 12 police, said Kamal Shah, the provincial police chief.

The injured were taken to two hospitals in Karachi. TV video showed some being treated on the floor in an overwhelmed ward of one of the hospitals.

There were no reports of any Americans hurt, a U.S. diplomat said on condition of anonymity.

The Cultural Center is a privately run English-language school and not affiliated with the U.S. government. It is located four houses from the U.S. Consul's residence on a leafy street, just outside gates manned by guards. The Consulate itself sits across a park.

After the first car exploded in Wednesday's attack, police sealed off the area as bomb disposal experts arrived to examine the wreckage. The second blast damaged the outer wall of the school, but the building itself was undamaged.

The bomb experts checked a third car parked a few yards from the school but found no more explosives.

Some Pakistani students from the center were injured in the first blast. Others were taking classes at the time and were told to stay inside.

Pakistan's Information Minister Sheikh Rashid Ahmed (search), who was in Karachi, condemned the attack and blamed "enemies of Pakistan."

"We are playing a front-line role in the war against terrorism, and terrorists are of course not happy," he told AP.

There was no immediate claim of responsibility for the attack.

About two hours after the second blast, two senior police officers received calls of a third bombing in another district of Karachi. Police and ambulances rushed to the scene, only to find it was a hoax.

Karachi (search) is Pakistan's biggest city and has been a scene of several bombings and terrorist attacks. On Tuesday, a package bomb exploded at a checkpoint in the port area, killing two people and wounding five.

In June 2002, a bombing outside the U.S. Consulate in Karachi killed 14 people.

In the past week, police have arrested seven militants from an extremist Islamic group, Harkat-ul-Mujahedeen al-Almi, blamed for a failed assassination plot on President Gen. Pervez Musharraf in April 2002 and the consulate attack. They also seized bomb-making materials and weapons, and police said the suspects had been planning further terrorist attacks.

Musharraf has enraged Islamic hard-liners for his support of the U.S.-led war on terrorism after the Sept. 11, 2001, attacks. In December, he narrowly escaped two assassination attempts 10 days apart near Islamabad.