Suspected militants attacked Army buildings near the US consulate in Pakistan's northwestern capital Peshawar on Saturday, police said.
Police said a number of armed fighters tried to get into a secure area close to the consulate and Army buildings early on Saturday morning and that exchanges of fire between the attackers and security forces were continuing.
"There target is not clear but they were trying to reach a very sensitive area. There is the US consulate and army offices and buildings in that area," Mr Karim Kha, a senior police official in Peshawar, told AFP.
"The US consulate is completely safe," he added.
Mr Richard Snelsire, a spokesman for the US Embassy in Islamabad, told AFP he had "no information right now" on whether the consulate was the intended target.
Police said the Army had sealed off the site of the attack, preventing anyone from entering, while intermittent gunfire continued.
An AFP reporter at the scene said Army and police had blocked all the roads into the area while helicopters patrolled the skies.
Mr Bashir Bilour, a provincial cabinet minister whose home is in front of the consulate, said: "The first round of firing continued for 30 minutes. I don't know what's going on but the army has sealed off the whole area and firing is still continuing."
"Soldiers have also entered my Hujra (Visitors compound). I cannot go outside," he added.
Bombs and attacks blamed on Taliban and Al Qaeda-linked militants have hit soldiers, government officials and civilians across nuclear-armed Pakistan since government troops besieged a radical mosque in Islamabad in July 2007.
Such attacks have killed more than 3,574 people in the past three years, concentrated largely in the northwest and border areas with Afghanistan, where 141,000 US and Nato troops have been fighting the Taliban for nine years.
A roadside remote control bomb on Monday killed two anti-Taliban militia men in Mattni on the outskirts of Peshawar and wounded five others, police said.