- Rebels fire at Interior Ministry official's car
* Interior Ministry official says truce still holds
* Iran welcomes ceasefire
(Adds Iranian comment)
By Mohammed Sudam
SANAA, Feb 12 (Reuters) - Shi'ite rebels shot at an Interior Ministry official and killed a soldier in northern Yemen on Friday, violating a truce announced hours earlier.
Yemen's government and rebel leader Abdul Malik al-Houthi agreed late on Thursday to a truce that began at midnight (2100 GMT). The truce was welcomed on Friday by Shi'ite Muslim Iran, which has criticised Saudi Arabia's involvement in the fighting on the government side.
Interior Minister undersecretary Mohammed al-Qawsi, whose car was shot at by rebels, told Reuters minor violations had occurred because not all rebel fighters were aware of the ceasefire, but that the deal still held.
He said rebels had killed one soldier and wounded seven outside the northern city of Saada.
"There are some small violations here and there, and there have also been some violations by rebels outside the city of Saada," Qawsi said.
The Yemeni government, which is also battling a resurgent threat from al Qaeda and a separatist movement in the south, had been exchanging ceasefire proposals with the rebels for several days. Both Houthi's rebels and the government issued statements late on Thursday calling for an end to the fighting, which the United Nations says has displaced 250,000 people.
Yemeni forces have been battling Houthi's supporters for more than five years and previous ceasefires have not lasted.
Qatar, a Gulf Arab gas producer and regional powerbroker, mediated a ceasefire in 2007 and a peace deal in 2008.
The rebels, from the Zaidi sect of Shi'ite Islam, have long complained of social, religious and economic discrimination in a country with a Sunni Muslim majority.
Yemen's many challenges have raised fears in the West and Saudi Arabia that it may become a failed state, allowing al Qaeda to use it as a base for attacks in the region and beyond.
In December it emerged that a Nigerian accused of trying to blow up a U.S.-bound airliner had links to Yemen, which borders the world's No. 1 oil exporter, Saudi Arabia, and sits at the entrance to Red Sea international shipping lanes.
Saudi Arabia was drawn into the conflict in November when the rebels seized some Saudi territory, complaining that Riyadh was letting Yemeni troops use its land for attacks against them.
Riyadh declared victory over the rebels last month, two days after they themselves offered a truce and said they had quit Saudi territory. The rebels say Saudi airstrikes have continued.
Saudi Arabia is the birthplace of Islam, and its ruling family and religious establishment enforce a strict form of Sunni Islam. Its involvement in Yemen has drawn criticism from Iran, which shares the rebels' Shi'ite Muslim faith.
Yemeni officials have accused Iran of backing Houthi's rebellion, but comments from an Iranian official on Friday suggested the latest truce was supported by all sides.
"Iran has always been in favour of an end to military conflicts and peaceful solutions, and sees that as a step towards strengthening national unity in Yemen," Foreign Ministry spokesman Ramin Mehmanparast was quoted as saying by Iran's ISNA news agency. (Additional reporting by John Irish; Writing by Lin Noueihed; Editing by Kevin Liffey)