At least four pro-government Yemeni soldiers were killed and three others injured on Tuesday when an explosive device struck their vehicle in the Red Sea port city of Mocha, a security official said.

"An explosion caused by an explosive device targeted a military vehicle carrying pro-government soldiers in Mocha, where anti-Houthi troops are deployed," the local security source said on condition of anonymity.

A medical team with an ambulance rushed to the bombing site and picked up the injured soldiers for treatment, according to local residents.

Fighters of the Houthi group had previously planted thousands of landmines and improvised explosive devices (IEDs) before their withdrawal from different areas located along the country's western coast.

The Houthi-laid landmines and IEDs continue to pose a real threat to the civilians despite the ongoing efforts exerted by the experts of the mine-clearing projects in Yemen.

Previous reports by humanitarian organizations said that Yemen has become one of the largest landmine battlefields in the world since the World War II.

The Iran-allied Houthi rebels seized the norther provinces including the capital Sanaa in late 2014, forcing Yemen's President Abdu-Rabbu Mansour Hadi and his government into exile in neighboring Saudi Arabia.

A coalition formed by Saudi Arabia and several other Arab countries intervened militarily in the Yemeni conflict to fight against the Houthis in March 2015, in response to an official request from Hadi to protect Yemen and roll back Iran's influence.