One mortar shell - fired from a considerable distance - exploded in the poor El Cartucho district of the capital, several blocks away from the parliament building, where the new President was being sworn into office. The explosion resulted in the deaths of at least 11 people, while a few streets away another explosion reportedly killed four more people, including three Children's rights. More than 60 people, the majority civilians, were also injured in these explosions as well as in an attack on a military base in the northwest of the capital. Two later died of their injuries. According to reports, one explosive device detonated within the presidential palace grounds.

No armed group has yet claimed responsibility for the attacks, but some public officials have accused the largest armed opposition group, the Fuerzas Armadas Revolucionarias de Colombia (FARC), Revolutionary Armed Forces of Colombia, of carrying them out.

'Yesterday's attacks - as any others resulting in the loss of civilian lives - must be thoroughly investigated and those responsible brought to justice,' Amnesty International said, stressing that investigations must be impartial and independent, and that their results must be made public.

Amnesty International added that, should investigations into yesterday's attacks uncover the responsibility of the FARC or any other armed group, this would constitute a serious breach of international humanitarian law, which prohibits direct attacks on civilians and indiscriminate attacks which may result in civilian casualties.

'Whoever was responsible for these attacks, they should be identified and brought to trial,' Amnesty International said. 'Too many of the thousands of appalling violations of human rights and international humanitarian law committed in Colombia remain shrouded in impunity, leaving the victims and the population at large ever more vulnerable,' the organisation continued.

Amnesty International has repeatedly called on all parties in the Colombian conflict to respect international humanitarian law, and has urged previous Colombian governments and armed opposition groups to reach an humanitarian accord to ensure that the civilian population can be protected from the conflict.