2 U.S. soldiers among 3 killed in suicide bombing in Afghanistan

KABUL, Afghanistan (WPVI) -- Two U.S. soldiers and one Polish soldier were killed when a Taliban attacker detonated his car bomb next to an international military convoy on Tuesday, a U.S. official confirmed.

Nearly 20 troops and civilians were wounded in the attack.

Security forces in full battle gear administered CPR to wounded comrades shortly after the 8:10 a.m. blast, which rattled nearby neighborhoods and sent a plume of smoke high into the sky.

The attack happened only a couple hundred yards from the U.S. Embassy, on a main Kabul road that leads to the airport.

The statement from the military coalition known as ISAF said five troops were wounded in addition to the three killed. The attack happened next to an ISAF base that houses many Americans.

The Taliban claimed responsibility for the attack.

The three military deaths - and a fourth in the country's east - brought the total number of international troops killed in Afghanistan this year to 59, at least 42 of whom were American.

The blast turned several vehicles into twisted metal and bloodied and dazed Afghan passers-by. Good Samaritans scooped up the wounded into their arms and carried them to medical workers. Ashmat Stanikzai, a spokesman for the Kabul police, said 13 Afghans were wounded. More than a dozen vehicles were damaged, the police said.

In the aftermath of the blast, Afghan and foreign troops secured the area as fire and rescue vehicles moved in. Investigators inspected an empty black SUV, its windows smashed and exterior pockmarked with shrapnel.

In a separate attack in the country's east, ISAF said Tuesday that one of its troops died after being shot by an individual wearing an Afghan army uniform. That raises the possibility that the service member died from a so-called insider attack carried out by an Afghan soldier, a serious problem over the last couple of years.

ISAF said it will continue to train and advise Afghan security forces "and does not view these incidents as representative of the positive relationship between our forces."

The spike in violence comes as the country's two presidential contenders continue negotiations to form some sort of national unity government. Afghans first voted in this year's presidential election in April, and voted again in a two-man runoff election in June.

President Hamid Karzai on Monday hosted the two candidates - Abdullah Abdullah and Ashraf Ghani Ahmadzai - in hopes of helping them reach agreement on a power-sharing government. The meeting ended without a deal.

The Associated Press contributed to this report.