The military parade by Yemen’s Houthi rebels in the Red Sea port city of Hodeidah violated a UN-brokered peace deal, the government said on Tuesday.
The Iranian-backed rebels and government agreed, during UN-led peace talks in Sweden last December, to a ceasefire and a troop withdrawal from Hodeidah’s three ports.
But the rebels are yet to withdraw their troops and uphold their side of the deal.
“The Houthis are showcasing its members in Hodeidah with four vehicles handed by United Nations to the Houthis for demining efforts,” Yemeni Minister of Information Muammar Al Eryani said on Twitter.
Flags of the Lebanese paramilitary group Hezbollah and Iran were flying from the rebels' armoured cars during the parade, the Yemeni minister said.
Mr Al Eryani said it was clear the Houthis had not withdrawn their troops from the port city.
The parade was held to mark the annual Quds Day that was launched by Iran's Ayatollah Ruhollah Khomeini, the leader of Iran's 1979 revolution.
The UN Development Programme announced last week that it had provided 20 Toyota Hilux armoured vehicles to the Yemen Executive Mine Action Centre to support its demining activities in the ports of Hodeidah, Ras Isa and Salif.
But Yemen’s government expressed concern that the UN’s vehicles were falling into the hands of the Houthis.
The UN agency said the vehicles were sent to ensure the safety and security of the deminers in Hodeidah, through which most humanitarian aid and imports enter Yemen.
Hodeidah became the focus of the war after the rebels used its ports to smuggle in Iranian weapons throughout the four-year civil war.
The port city is under the rebels' control while Yemeni forces aligned with the government wait on its outskirts.
“This development comes five months after the Sweden deal, which implemented a ceasefire and an end to armed exhibitions in the city,” Mr Al Eryani said.
Although the UN last month announced that the Houthis had withdrawn, the government said the rebels had kept their fighters at the ports by disguising them as coastguards and in police uniforms.
The government also accused UN envoy Martin Griffiths of turning a "blind eye".
The armed men in the parade are the coastguards who are set to take over Hodeidah once the rebels withdraw, Mr Al Eryani said.
Officials in the government have shown frustration with the UN envoy over his endorsement of a supposed Houthi withdrawal.
They have stopped all communications with Mr Griffiths until he re-evaluates his stance.
"I think what is best for the envoy is to resign because he has proven to be a biased and one-sided towards the rebels," Hamza Al Kamaly, Yemen's deputy minister of youth, told The National.
"This will ease the recent tensions between the government and the UN."
Yemen has been dragged into a civil war since 2014 after the Iranian-backed rebels seized its capital, Sanaa, and forced out its internationally recognised government.
