KABUL, Afghanistan - A rare rocket attack in the Afghan capital last night demolished two rooms of a mud-brick home and killed three teenage sisters, the family and police said.

The rocket attack on the southern end of Kabul landed on a house adjacent to an Afghan police training center. The attack crushed a mud home and killed the sisters, ages 13, 15 and 16, said Sayed Farah Muz, the girls' uncle.

"There are 40 countries in Afghanistan, and still we are hit by rockets. What is the benefit?" said Sayed Shah Barat, a cousin of the girls. "The Iraqi people hit Bush with their shoes, but we should do the same with our leaders."

There are 41 nations involved in NATO's security coalition in Afghanistan.

The house hit by the rocket was a simple six-room home that housed about 20 people, Barat said. Men swept up the shattered bricks of mud while women mourned out loud in another room.

Gen. Ali Shah Paktiawal, the head of criminal investigations for the Kabul police, said two rockets were fired into Kabul after nightfall.

Kabul once suffered greatly from rocket fire, during the country's 1990s civil war, but such attacks have been a rarity the last several years.

Elsewhere, a suicide car bomber attacked a police checkpoint yesterday in southern Afghanistan, killing three police officers and two civilians in the Arghandab district of Kandahar province, local police chief Zamarai Khan said. Four police and one civilian were wounded.

Many outlying districts of Kandahar province are teeming with Taliban fighters. The United States plans to send thousands of new troops to the region over the next six months.

Meanwhile, the U.S. coalition and Afghan forces killed six militants during a patrol in southern Afghanistan.

The coalition said yesterday that the combined forces were on patrol in Helmand province Thursday when they spotted militants pulling weapons from a hiding spot. The combined forces killed the fighters and destroyed the weapons.