Malawi on Thursday unearthed four more bodies following the grim discovery of a grave containing the remains of 25 men suspected to be Ethiopian migrants, police said.
The latest finds were made at four separate locations some two kilometres (1.2 miles) from the mass grave, bringing the toll so far to 29.
The dead are suspected to be migrants heading for South Africa -- the continent's most industrialised economy and a magnet for poor workers from elsewhere on the continent.
"Malawi is a country of transit for migrants from the Horn of Africa travelling along what is known as the Southern Route from as far north as Ethiopia in a bid to reach South Africa in search of employment," said the International Organization for Migration (IOM).
It said in a statement that the latest tragedy highlighted the "urgent need" to tackle the complexities of irregular migration.
"Irregular migration along the Southern Route facilitated by an intricate network of smugglers and traffickers is fraught with danger," the IOM wrote.
Investigators found the four bodies while combing the area, police spokesman Peter Kalaya told AFP.
Villagers in the northern area of Mzimba, about 250 kilometres north of the capital Lilongwe, stumbled on the mass grave while collecting wild honey in a forest earlier this week.
Police said evidence gathered from the site on Wednesday indicated the 25 victims were Ethiopian males aged between 25 and 40.
Kalaya said that between January and September this year, authorities had intercepted 221 illegal immigrants, 186 of whom were Ethiopians.