Military officers travel in a vehicle along a road in Garissa, in this still image taken from video shot on April 2, 2015.[Photo/Agencies]

NAIROBI - Kenyan police on Thursday circulated a photo of a senior Al-Shabaab leader, whom they believe is behind the university attack in Garissa that has so far killed 17 and injured 65 others.

The police placed a 54,350 U.S. dollars bounty on the head of Mohamed Kuno, who is Al-Shabaab's military commander in Lower Juba region in southern Somalia. He is currently in charge of external operations against Kenya.

"He (Kuno) commands the militia along the border and is responsible for cross-border incursions in the country. In the recent past, he has intensified attacks in Northern Kenya and Coast region, particularly in Garissa, Mandera, Lamu," the police said.

Sources said the suspect was aided by two local youths to conduct surveillance on the Moi University Garissa campus.

The authorities said death toll could rise further after the militants stormed the university near the border with Somalia, taking students hostage and battling security forces for several hours.

Police and soldiers surrounded and sealed off the campus, and were attempting to flush out the gunmen, according to police chief Joseph Boinett.

The Al-Shabaab terror group, which has links to Al-Qaida network, has claimed responsibility for the 5:30 a.m. raid, saying it was holding many Christian hostages inside.