Kenya promises to fight back after al-Shabaab massacre

The bodies of dozens of students massacred by Somalia's al-Shabaab fighters at a Kenyan university have arrived in the capital Nairobi, as grieving relatives faced a desperate wait to receive the remains of their loved ones.

The day-long siege of Garissa University killed 147 people, mostly students, in Kenya's deadliest attack since the 1998 bombing of the US embassy in Nairobi, and the bloodiest ever by the al-Qaeda-affiliated group.

Survivors recounted how the masked gunmen taunted students before killing them, including forcing them to phone their parents to urge them to call for Kenyan troops to leave Somalia - before shooting them anyway.

Some reported smeareding blood from their dead friends over their bodies to pretend they too had been shot.

"There were bodies everywhere in execution lines, we saw people whose heads had been blown off, bullet wounds everywhere, it was a grisly mess," said Reuben Nyaora, an aid worker who helped the wounded.

Others appeared to have been killed by knives.

The day-long seige ended with four gunmen being killed by Kenyan troops and one suspect reportedly arrested.

At least 79 others were wounded in the attack on the campus, which lies near the border with Somalia.

Al-Shabaab also carried out the Westgate shopping centre massacre in Nairobi in September 2013, when four gunmen killed 67 people in a four-day siege.

There were bodies everywhere in execution lines... it was a grisly mess. Reuben Nyaora, aid worker

On Friday, a huge crowd survivors and relatives of those killed or missing gathered at the university gate.

"I am so worried, I had a son who was among the students trapped inside the college, and since yesterday I have heard nothing," said Habel Mutinda. "I tried to identify his body among those killed... I have to do that before the body goes bad in the heat."

Kenya promises to fight back

Kenya's interior minister, Joseph Nkaissery, promised his government would not "be intimidated by the terrorists who have made killing innocent people a way to humiliate the government. We shall win this war against our enemies".

The gunmen stormed the university at dawn as students were sleeping, and shot dead dozens of people before freeing Muslims and taking Christians and others hostage.

Maureen Manyengo, a 21-year-old student from western Kenya, said she hid inside her wardrobe after seeing several friends killed.

"I could hear the attackers telling my friends, 'Do not worry, we will kill you, but we will die too'," she recalled, saying the attackers spoke in Swahili, not Somali.

"I could also hear them, saying 'You will only be safe the day your president removes the soldiers from Somalia'."

Al-Shabaab said the attack was "revenge" for the presence of Kenyan troops in Somalia as part of the African Union's force supporting the government in Mogadishu.