Thousands of mourners and survivors came together in Nairobi, Kenya, on Sunday to commemorate one year since gunmen from the militant group al-Shabab stormed the capital's Westgate Mall, where they staged a four-day massacre. Al-Shabab claims the attack was an act of revenge against Kenya for the presence of their troops fighting extremists in Somalia.

According to Kenyan officials, 67 people were killed during the attack, in which the attackers hunted down shoppers in supermarket aisles and singled out non-Muslims for execution.

'High alert'

On Saturday, Kenyan police chief David Kimaiyo said Kenyan security forces remained on high alert for the anniversary, asking Kenyan's to be "extra vigilant" in the coming weeks.

A memorial exhibition at the National Museum opened Tuesday

The anniversary comes just weeks after the Shebab's reclusive leader and alleged mastermind of the Westgate attack, Ahmed Abdi Godane, was killed in a US air strike in southern Somalia, which al-Shabab have vowed to avenge.

"We are prepared in case of anything. Specialized units are on the ground and we have intensified patrols during this period of the anniversary," Kimaiyo told reporters.

'Scarred nation'

Around 2,500 people, many of whom were survivors or bereaved families, held inter-faith prayers and a memorial procession in Nairobi's Karura forest where a plaque bearing the victims' names will also be unveiled.

Bereaved relatives will also lay wreaths at a garden in Karura forest, where 67 tree seedlings were planted last year in memory of the 67 massacre's victims.

A candlelight concert at the National Museum, the venue of a memorial exhibition that opened on Tuesday, will bring the anniversary's commemorations to a close later today.

"The nation may have been seriously scarred, but we shall never be broken as people," Kenya's First Lady Margaret Kenyatta said during the official opening of the exhibit.

All four gunmen, who were aged between 19 and 23, are believed to have died in the mall. The trial against four alleged accomplices is set to resume on Tuesday.

'Heroic sacrifices'

In an editorial published by the Sunday Nation, Kenyan President Uhuru Kenyatta vowed that his country would not give in to the Islamist militant group.

"We have pushed with greater resolve to defeat terrorists and criminals who target innocent people living in Kenya. We have maintained our focus in Somalia, where our defense forces continue to incur heroic sacrifices to defeat terrorists and their sponsors," he wrote.

Attacks on Kenya have continued in the year following the Westgate Mall attack, with al-Shabab also claiming responsibility for the deadly attacks on the coastal province of Lamu in June in which at least 22 people were killed.

ksb/tj (AFP, AP)