Yemen’s Gulf-backed government accused the Lebanese Shi’ite Muslim militia Hezbollah on Wednesday of training Houthi forces, fighting alongside them and planning attacks in Saudi Arabia.

Yemen’s government and its Gulf partners have long accused Hezbollah’s ally Iran of backing the Houthis and seeking to transform the group into a replica of the Lebanese militia to use as a proxy against its main regional rival, Saudi Arabia.

Its latest assertion, in a statement carried by official media, is based on “many documents and physical evidence”, found in military positions abandoned by the Houthis, which it said Hezbollah would not be able to deny.

Both Iran and Hezbollah reject accusations they have provided military aid to the Houthis.

A video recording that Saudi officials gave to Reuters and other media and purported to show a Hezbollah operative with the nickname “Abu Saleh al-Libnani (Lebanese)” sitting in a tent discussing tactics with Houthi fighters last summer.

Most of the video was muted, but during one of the brief segments with sound he was shown saying “I have a special operation in the heart of Riyadh”.

Asked by one of those listening if it would be a suicide operation, he answered “maybe a suicide operation. What we do is suicide operations.” Reuters could not independently verify the content of the video or the identity of the man named as Abu Saleh, who spoke in Arabic with a Lebanese accent.

Saudi Arabia is leading an Arab coalition against the Houthis and forces loyal to former president Ali Abdullah Saleh in a bid to restore the internationally recognised government of President Abd-Rabbu Mansour Hadi.

Although both Iran and Hezbollah have given vocal support to the Houthis, dismissed Hadi’s government as illegitimate and condemned Saudi involvement in the civil war, they deny giving the group military aid.