By Kylie Morris BBC

The MP is suspected of involvement in a raid in January

More than 50 people have died in the wave of attacks which began with a raid on an army camp in January.

Police say they suspect the governing party member of parliament Najamudeen Umar may have been involved in the raid, which killed four soldiers.

The Muslim MP has denied the allegation.

Mr Najamudeen is an MP from Narathiwat province and as such has parliamentary immunity against arrest.

While the police have succeeded in gaining arrest warrants for the MP and eight others on charges including treason and the theft of weapons, parliamentary approval must be given before he can be arrested.

Police criticised

The leader of his party, the Thai Prime Minister Thaksin Shinawatra, has said that the issuing of the warrant does not mean Mr Najamudeen is a wrongdoer but that he will receive a fair trail.

Police took steps to arrest the MP because of information they say they gleaned from another suspect in the case.

A Thai police officer was among those recently killed

But they have been sharply criticised for publicly identifying the politician and another MP and senator prior to any formal charges.

In the latest violence in the south a police sergeant was shot and killed in Songkhla and a village elder wounded in Narathiwat.

Martial law still applies across the Muslim majority provinces in the country's south.

The government says it plans to install closed circuit television in state buildings and other sensitive areas to halt the escalation in what it called urban terrorism.