|Kenya said it was tracking the arms caches and would strike al-Shabab bases where the arms were delivered [Reuters]
The Eritrean government has denied that it sent weapons to al-Shabab engaged in battle with Kenyan troops in southern Somalia.
The United Nations has accused the African nation of posing a threat to the East African region, partly by financing
Somalia's anti-government fighters.
Media reports in Kenya and Somalia claimed that Eritrea had sent two aircraft with weapons to help al-Shabab.
"The government of Eritrea states categorically that these accusations are pure fabrications and outright lies as Eritrea has not sent any arms to Somalia," Eritrea's foreign ministry said in a statement on Wednesday.
"Tuesday's baseless accusations are the latest product of a misinformation campaign orchestrated to undermine Eritrea and frustrate its constructive regional and international engagement."
The denial of blame follows a July report, by the UN's Monitoring Group on Somalia and Eritrea, which said that illicit flights with weapons or fighters for al-Shabab could be originating from Eritrea, Yemen or the UAE.
The UN report said Eritrea consistently denies providing military support to armed groups in Somalia, but that "new information ... not only confirms many previous allegations of Eritrean military involvement, but also offers firm grounds to believe that Eritrea still retains active linkages to Somali armed groups."
Eritrea gives about $80,000 a month to al-Shabab-linked individuals in Nairobi, the report said.
Speaking to Al Jazeera, Araya Desta, Eritrea's ambassador to the UN, said: "The UN so-called Somalia-Eritrea monitoring group did not accuse Eritrea of sending arms or finance. What it said was there is no evidence that Eritrea has sent arms or finance.
"Eritrea's principal stand is clear. We have been saying that military will not bring peace in Somalia, that Somalis should be given the opportunity to sit and discuss their own problems and come out with their own solutions."
Eritrea said Ethiopia, which routinely accuses its neighbour of supporting the fighters, is behind the allegations.
The UN's July report said that al-Shabab controls two large airports and one former military airport with asphalt runways. Al-Shabab may then be capable of chartering and receiving deliveries by aircraft, it said.
A Kenyan military spokesman, Emmanuel Chirchir, on Tuesday said two consignments of arms had been flown into central Somalia, landing in the town of Baidoa, but declined to speculate where the cache had come from.
Chirchir then said Kenya was tracking the arms caches and would strike any rebel bases where the arms were
delivered, naming ten rebel bastions on Kenya's hit-list.
Chirchir sent a warning over the social media website Twitter, informing residents of the towns that they would come under continuous military attack.
Kenya sent hundreds of the troops to Somalia in mid-October in pursuit of al-Shabab fighters it blames for a string of kidnappings in Kenya.