( CNN )- Four of the 12 people wounded in the weekend bombing of an Islamabad restaurant are U.S. FBI agents, the bureau confirmed Sunday.
The attack occurred Saturday when a bomb was hurled over a wall surrounding the Luna Caprese restaurant, an outdoor cafe frequented by Westerners, journalists and diplomats.
Four FBI personnel were "slightly injured" in the blast, FBI special agent Richard Kolko said Sunday in a written statement.
In addition to wounding the agents, the explosion killed a Turkish woman and wounded a fifth American, three Pakistanis, a person from the United Kingdom and someone from Japan, authorities said.
A high-ranking federal source had earlier told CNN that the agents' wounds included deep lacerations, concussions and fractures.
The four, who were eating dinner together at the time of the attack, were not believed to have been targeted, the source added.
An air ambulance took the agents to a hospital.
Government officials have not said who they believe is responsible for Saturday's attack, but they suspect al Qaeda and Taliban-linked militants from Pakistan's tribal region, who have carried out similar attacks in the past.
An FBI spokesman in Washington had no comment, but National Security Council spokesman Gordon Johndroe told CNN that President Bush "appreciates the hard and dangerous work that U.S. officials engage in around the world, and our thoughts are with them and their families as they recover from this attack."
He added, "The U.S. condemns the latest in a series of bombings in Pakistan that have taken the lives of over 500 people since January.
"Extremists that are targeting innocent Pakistanis, as well as Americans and others in the international community in Islamabad and elsewhere, must be stopped. These terrorists offer nothing but death and destruction, and we will continue to work with the Pakistani government as they go after these thugs."
Saturday's bombing came on the heels of another deadly attack targeting a federal investigative agency. Last week, a suicide attack killed 25 people at a federal police building in Lahore. Officials say the building housed a counter-terrorism unit funded by the U.S. and its allies in the war on terror.
Also on Sunday, a missile strike near the Afghan border killed about 20 people, according to state-run Pakistan Television.
A house that belonged to a suspected militant leader was destroyed, according to a local tribesman, The Associated Press reported. It's unclear where the missiles came from, but in the past, U.S.-led coalition forces based in neighboring Afghanistan have launched attacks inside Pakistan's border.
The spate of violence comes at a politically sensitive time in Pakistan. Parliament is expected to reconvene Monday, which will place in power opponents of President Pervez Musharraf.
The U.S. Embassy posted a notice on its Web site Saturday warning American citizens to keep a low profile and avoid areas where Westerners are known to congregate