Yemen's president has called on Iran to stop backing armed groups in his country after coastguards seized a ship carrying missiles and rockets.
Abd-Rabbu Mansour Hadi's message came amid speculation the weapons originated in the Iran.
Tehran has denied any connection to the weapons; Yemen has asked the UN Security Council to investigate.
The Sanaa government fears Iran is working with separatists and rebels in the south to destabilise the country.
The weapons were found aboard a vessel intercepted off Yemen's coast on 23 January in an operation co-ordinated with the US Navy.
Officials say the shipment included anti-aircraft missiles, Katyusha rockets, rocket propelled grenades and C4 explosives.
Reports suggest the weapons were destined for the Red Sea port of Al-Mukha, and that their intended recipients were the Houthis - a Shia insurgent group based in northern Yemen.
Government official Abdel-Rashid Abdel Hafez said Mr Mansour Hadi had contacted his Iranian counterpart, Mahmoud Ahmadinejad, to demand Tehran stop smuggling in weapons.
Mr Abdel Hafez gave no more details about the correspondence.
Correspondents say the discovery of the shipment will further sour ties between Iran and Yemen.
Yemen has requested the shipment be investigated by the UN Security Council's group of experts that monitors compliance with the Iran sanctions regime.
If the sanctions committee finds the shipment originated in Iran, that would breech a ban on arms exports.
Yemen is considered a stronghold of al-Qaeda in the Arabian peninsula (AQAP). Militants have gained ground because of the weakness of the central government.
A US-backed military offensive last year pushed the militants back from some of its strongholds in the south, but AQAP is viewed by the US as as the most active and deadly wing of al-Qaeda's terror network.