KABUL, Afghanistan - Defense Secretary Robert Gates, on his first visit to Afghanistan, said yesterday that there had been a "significant increase" in cross-border attacks from Pakistan, adding his voice to a chorus of U.S. and international officials who have begun taking Pakistan to task for harboring Islamic extremists.

Gates praised Pakistan as a "strong American ally in the war on terror," but he also said that there was a "problem" in Pakistan's border areas and that "al-Qaeda networks are operating on the Pakistan side." He said the United States needed to "work with Pakistan" to reduce the violence and attacks emanating from within its borders.

Speaking at a news conference here with Afghan President Hamid Karzai, Gates was the latest of several U.S. and U.N. officials to publicly raise the border issue after several years of international silence because of Pakistan's cooperation in the hunt for al-Qaeda fugitives.

U.S. military officials cited year-end statistics showing a sharp increase in insurgent attacks here, especially by the revived Taliban militia, and predicted a strong burst of violence in the spring.

Lt. Gen. Karl Eikenberry, the senior U.S. commander in Afghanistan, told journalists traveling with Gates that the number of suicide attacks had increased from 27 in 2005 to 139 in 2006. He said that remotely detonated bombings had more than doubled, from 783 to 1,677, and that armed attacks had nearly tripled, from 1,558 to 4,542.

The violence led to more than 4,000 deaths in Afghanistan last year. It was by far the bloodiest year in the country since 2001, when a U.S.-led invasion drove the Taliban from power.

Gates, who was sworn in last month as defense secretary, said he would be "strongly inclined" to recommend a troop increase if commanders believed it was needed, the Associated Press reported.

Eikenberry said he wanted to extend the combat tours of 1,200 soldiers in Afghanistan to help stem the rising violence, the news service reported. There are 24,000 American troops in Afghanistan, 11,000 operating under command of the NATO alliance and the rest under U.S. command.

The senior U.S. military spokesman in Kabul, Col. Thomas Collins, said that enemy forces were taking advantage of a peace pact reached in September between Pakistan's government and tribal leaders near the Afghan border. The government had promised that the agreement would curb extremist activity and cross-border movements into Pakistan.

In the last few days, several incidents have appeared to bolster the new international concern about Pakistan's role in violence.

Last week, officials said, two groups of insurgents were tracked crossing from Pakistan into Afghanistan, where they were attacked by U.S. and Afghan forces. At least 30 insurgents were killed. Taliban officials reportedly called on villagers in the Pakistani tribal areas to hold special funerals for them as Islamic martyrs.

Yesterday, Afghan police said they had caught a suicide bomber trying to blow up a foreign military compound in Kabul. They said he was from North Waziristan, the Pakistani border region where officials made the truce with local officials in September.

Pakistani officials deny they are abetting Islamic extremists or cross-border attacks.

Pakistan: 8 Killed In Raid Near Border

Pakistani helicopter gunships attacked a suspected al-Qaeda hideout in forest near the Afghan border yesterday, killing at least eight people and sparking anger among tribesmen who said the dead were woodcutters, not terrorists.

Pakistan's army said intelligence sources had confirmed the presence

of 25 to 30 extremists, including four or five unidentified al-Qaeda members, occupying five compounds in the area of Zamzola - a village in South Waziristan about two miles from the frontier.

Pakistani forces backed by Cobra gunships attacked them, destroying three of the compounds.

An army spokesman, Maj. Gen. Shaukat Sultan, said eight extremists were killed and 10 wounded, none of them "high-value targets."

- Associated PressEndText