At least 100 Federal Police have been deployed to the South West State administrative capital Baidoa to boost security in the December 5 election.
A plane carrying the police officers landed at the Baidoa Airport on Friday.
The deployment follows last week arrival of at least two battalions of Ethiopian troops.
African Union Mission In Somalia (AMISOM) on Wednesday affirmed it's committment to ensure security in the elections.
The regional parliament will vote to decide who the next leader of South West will be to replace Sharif Hassan Adan who recently quit the race after he announced his resignation.
The race pits former Al-Shabaab deputy leader against pro federal government candidates.
Robow was on Sunday officially cleared by the South West State Electoral Commission to contest in the December elections despite early protest by the Federal government seeking to have him barred.
He got a major boost in his campaign when five hopefuls withdrew from the race to support his candidature.
Government backed former spy Chief Hussein Osman Hussein, former Trade Minister Abdiaziz Hassan Laftagareen and former Somali envoy to Uganda Siid Ahmed Muse held will be challenging Robow in the race.