Taliban insurgents began their annual spring fighting season with a series of deadly attacks across Afghanistan.

At least six people were killed and more than 50 others wounded in a Saturday attack on the northern city of Kunduz, said the head of the provincial council there.

Mohammad Yusouf Ayubi added that hundreds of people fled their homes as the sound of gunfire and explosions echoed from the city’s outskirts.

Kunduz lies at a strategic crossroads in the heart of a major agricultural region, with easy access to much of northern Afghanistan as well as the capital, Kabul.

The Taliban declared the start of their annual spring offensive on Friday. The insurgents have managed to keep up a steady tempo of attacks even during the harsh winter months in recent years.

In the western Ghor province, the Taliban ambushed a police convoy on Friday afternoon, killing seven security forces and igniting a battle that raged for several hours, said Abdul Hai Khateby, the governor’s spokesman.

In the northern Baghlan province, the Taliban killed seven police and wounded eight in an attack on checkpoints late Friday, said Safder Mohsini, head of the provincial council. The insurgents also attacked a district headquarters in the eastern Nangarhar province late Friday, killing two police, said Attahullah Khogyani, the governor’s spokesman.

Nangarhar Gov. Shahmahmood Miakhel said Afghan forces repelled the attack after reinforcements arrived.

The insurgents have continued to launch daily attacks on security forces despite holding several rounds of peace talks with the United States in recent months.