DUBAI (Reuters) - Saudi Arabia's King Salman has relieved Health Minister Ahmed al-Khatib of his post, removing a second minister handling social welfare issues in the space of a month as he reshapes the cabinet soon after coming to the throne.

Mohammed bin Abdulmalik bin Abdullah Al Al-Sheikh will be acting health minister, state news agency SPA said in a brief report on Saturday. It did not say why Khatib was relieved.

In early March, Salman removed the housing minister, a day after pledging to speed efforts to end a shortage of homes in his first address to the nation since becoming monarch in late January.

This followed a cabinet reshuffle in late January in which Salman appointed new ministers to several portfolios including agriculture, education and information. He also reorganized the policy-making apparatus, abolishing some committees and creating a new economic council chaired by his son.

Social welfare problems such as a lack of affordable housing, uneven provision of health care and unemployment are key political issues in Saudi Arabia.

Since taking the throne, Salman has appeared willing to tackle them aggressively. Last month the cabinet approved the politically sensitive idea of taxing undeveloped land in order to force more land out into the market and ease the housing shortage.

(Reporting by Andrew Torchia; Editing by Olzhas Auyezov)