At least 10 people were injured in a hand grenade attack on a Pakistani Air Force (PAF) engineering center in the country's northwest city of Nowshera on Tuesday morning, said security sources.

Local media quoted unidentified security sources as saying that ten people including five soldiers and five civilians were injured in the attack.

The attack took place at about 11:00 am local time when two people riding a motorbike hurled two hand greades at a crowd gathering outside a gate of the PAF engineering center for enrollment in the Risalpur area of Nowshera, a city some 120 kilometers northwest of Islamabad.

All the injured have been shifted to a military hospital in the city, and their conditions are yet to be known.

Local media reported earlier that three people were killed and about 15 others injured in the blast.

Security forces have sealed off the area and at least five suspects have been arrested in the search operation, reported local media.

No group has claimed responsibility for the attack.