Security agents have arrested 17 people allegedly trained in Pakistan who they believe planned to launch suicide attacks in three Afghan provinces, Afghanistan's intelligence agency said.

The 17 were detained in Nangarhar, Kunduz and Kabul provinces and told authorities they attended militant training camps in neighbouring Pakistan, Said Ansari, spokesman for Afghanistan's intelligence agency, said Wednesday. It was unclear when they were detained.

Ansari said militants in Pakistan encourage fighters to carry out suicide attacks by telling them girls in Afghanistan are wearing un-Islamic clothes or studying subjects in school unrelated to Islam.

The would-be bombers trained in Shamshatoo, an Afghan refugee camp near Peshawar and at another camp near Data Khel in Pakistan's semiautonomous North Waziristan tribal region, Ansari said.

"They are telling those people that they should conduct suicide attacks because the foreigners who are here are doing bad things in Afghanistan that are unacceptable in an Islamic country,'' Ansari told a news conference.

Few details were provided on the 17 detainees. One was an Afghan, said Ansari, who did not reveal the nationalities of the others.

Pakistan's government signed a deal with pro-Taliban militants Sept. 5 to end fighting that broke out in North Waziristan after the U.S.-led invasion of Afghanistan in October 2001. Under the deal, militants agreed to not carry out violent acts, fan extremism or send fighters into Afghanistan to attack local forces or foreign troops.

Pakistan's top military spokesman said Pakistan had no information on the arrests.

"If there is any such evidence, this should be shared with us officially through the fastest channels so that we can verify it and take appropriate action,'' Maj.-Gen. Shaukat Sultan said.

"Sharing of such information with the media is absolutely unwise and illogical.''

Taliban-linked militants have stepped up attacks this year, including use of suicide and roadside bombs. It's been the deadliest period in Afghanistan since late 2001 when U.S.-led forces ousted the Taliban regime for hosting Osama bin Laden.

Ansari said 160 civilians have been killed and 500 wounded in 90 suicide attacks over the last two years and most suicide attackers were Afghan, Pakistani or Chechen. He said there have been 72 suicide attacks since March 21.

Some 184 schools have also been burned down or destroyed this year, Ansari said, compared with about 145 that were attacked last year, the Education Ministry said.

Afghan officials said Pakistan turns a blind eye toward militant activity in its tribal areas and those fighters regularly stream across the border into Afghanistan.

Pakistan denies it doesn't do enough to stem the flow of militants and weapons from its territory into Afghanistan but acknowledges the porous nature of the border makes it virtually impossible to completely seal.