Kabul  - An Afghan teacher who preached against suicide bombings was killed by unknown armed men in the northern part of the country, officials said on Wednesday.

The school teacher was killed by gunfire in Archi district of the northern province of Kunduz on Tuesday night, according to Juma Khan, the district administrative chief.

He said the teacher had recently condemned the wave of suicide bombings in the country and termed them as "un-Islamic" during a speech at a gathering in the district.

Taliban militants have killed several Afghan clerics in the past for giving anti-Taliban speeches. Suicide bombing is a frequent Taliban and al-Qaeda tactic.

Meanwhile, Afghan intelligence agents arrested a foreign would-be suicide bomber and his Afghan associate and seized 200 kilograms of explosive packed in a vehicle in northern Balkh province, a government spokesman said.

Hamza, 20 years old, who is from Tajikistan but was born in Pakistan and studied in an Islamic religious school in the Pakistani city of Karachi, was arrested while he was trying to enter Mazar-e-Sharif city, the capital of Balkh province, on Tuesday, Sayed Ansari, spokesman for intelligence service, told reporters on Tuesday night.

He said that his Afghan guide had also come from Pakistan and intended to carry out a terrorist attack in the province.

"The terrorists have confessed and said that they were tasked by a person called Saifullah, who is a member of the al-Qaeda network and now lives in North Waziristan of Pakistan," Ansari said.

More than 3,000 German soldiers are based in the northern region, including Mazar-e-Sharif city, as part of some 50,000-member NATO troop contingent in the country.

The Taliban in their newly announced operation, dubbed as Ebrat (Lesson), have warned they will extend their activities, which have so far been heavily concentrated in the southern and eastern regions, to the relatively peaceful northern and western regions.

On April 9, a suicide attack against a German military convoy in northern Baghlan province left only the bomber dead, while a roadside attack in northern Kunduz province in late March wounded three German soldiers, two of them critically.

The spokesman also said a Pakistani national was arrested in the southern Zabul province. The suspect allegedly had come to Afghanistan recently along with other three Pakistani nationals to carry out terrorist attacks inside the country.

The latest assertions by Afghan officials regarding militants entering Afghanistan from Pakistani territory follow an attack against Afghan President Hamid Karzai last month.

Amrullah Saleh, chief of the National Directorate of Security, the Afghan intelligence service, claimed the attack on Karzai was hatched inside Pakistan.

The recent accusations have strained relations between the already hostile neighbors, who often blame each other for not doing enough to clamp down on Taliban and al-Qaeda militants who are heavily entrenched in the border areas between the two countries.

Both Kabul and Islamabad are close allies of the US. (dpa)