BAGHDAD — A would-be suicide bomber tackled by guards on the doorstep of a mosque in northern Iraq is a Syrian linked to al-Qaida in Iraq, police said today, detailing the capture that could provide new leads on other insurgent operations.

The details emerged a day after Ammar Afif Hamadan, 19, was arrested by guards who became suspicious as he approached the main gate of a Shiite mosque in the disputed city of Kirkuk.

His capture could give authorities information about insurgent operations in northern Iraq and smuggling routes used to bring people from Syria — long considered one of the main pipelines for insurgentsfrom across the region.

It also comes as a welcome success story for Iraqi security forces, troubled by public complaints following a series of recent high-profile bombings in Baghdad and elsewhere.

According to a police officer involved in the investigation, Hamadan fired a pistol at one guard who tried to stop him. Then another guard tackled him as he continued toward the mosque's main hall, grabbing the attacker's hands to prevent him from detonating an explosives belt.

The belt was packed with grenades containing about 55 pounds (25 kilograms) of explosives that were connected to the suspect's digital watch, the officer said, speaking on condition of anonymity because he wasn't authorized to release the information.