At least two policemen have been killed in a gun attack outside the US consulate in the Pakistani city of Karachi.
Two of the wounded policemen
A number of policemen were also injured.
The incident comes despite heavy security around the building.
Last June, 12 people died in an attack on the consulate.
Initial reports said several men took part in the attack, opening fire with automatic weapons.
The scene of the shooting
Later reports speak of one attacker.
"A man carrying a weapon approached the picket and when a policeman checked him, he opened fire at the policeman," Karachi police chief Tariq Jamil told the AFP news agency.
"The assailant then grabbed the policeman's sub-machinegun and opened indiscriminate fire."
The consulate is protected by cement barricades to prevent car bomb attacks.
Police have arrested the suspected attacker.
"The suspect is not linked to al-Qaeda, but connected to some local Pakistani extremist group," a senior police official told Reuters news agency.
An intelligence official told the AFP news agency: "The policemen were hate-targets because they were protecting Americans."
Security is a continuing problem for the authorities in the city.
The US drastically reduced its staffing at its consulate after last June's attack and moved to a different building.
A US spokesman said none of its Karachi staff had been involved in Friday's shooting.
The attack comes just two days ahead of a planned anti-American and anti-war protest in Karachi.
Organisers of the protest, called the Million Man March, say it will be the biggest so far held in Pakistan.
History of violence
Last May a bomb attack outside the Sheraton hotel killed 11 French nationals and three Pakistanis.
And in December three people were killed in an attack at the Macedonian consulate in Karachi.
The dead - all Pakistani - had been tied up, gagged and killed before an explosion at the office, and doctors said the throats of two of the victims had been slit.