DUBAI – Security forces arrested 21 separatists trying to provoke rioting during demonstrations in a southern provincial capital as Yemen increased security to guard against attacks, the government said on Sunday. Hundreds of people demonstrated in Dalea on Saturday against earlier arrests, with some carrying the flag of the former South Yemen, which united with the North in 1990, residents and pro-southern websites said. "The chief of security in Dalea said security forces were able to prevent and disperse a number of "elements" attempting to cause chaos, riot, and who were chanting slogans aiming at spreading hatred and causing division," the defence ministry said in its online newspaper yesterday. Yemen, the poorest Arab country, struck a truce on February 11 with rebels who have been fighting over religious, economic, and social grievances in the north. On Saturday it imposed tougher security measures in Dalea, where separatist tensions have been rising. These included a ban on carrying weapons in public, two days after a policeman was shot dead in an ambush in a nearby province. The policeman's death on Thursday brought to four the number of people killed in attacks on security personnel in the south in a week as authorities mounted arrest sweeps targeting separatists. People in the south, home to most Yemeni oil facilities, complain that northerners have abused the 1990 agreement uniting the country to grab resources and discriminate against them. Meanwhile, Saudi Arabia's Second Deputy Premier and Minister of Interior Prince Naif bin Abdulaziz yesterday welcomed visiting Yemeni Premier Ali Mohamed Majur and accompanying delegation to the Kingdom. Prince Naif said in a press statement that took place after the Yemeni Premier arrived in Riyadh that security cooperation among security bodies in the two countries is at its best and led to positive results and it would make a strong impact both in the present and in the future. "A number of issues of mutual interest would be discussed as I meet the Premier," he added. Prince Naif asserted that the Kingdom and Yemen were working together to promote security levels on their shared border. On his part, the Yemeni Premier said that he would convey Yemeni President, Ali Abdullah Salih greetings to the Custodian of the Two Holy Mosques King Abdullah bin Abdulaziz. The 19th session of Saudi-Yemeni Co-ordination Council would tackle a wide range of issues, accords and memos of understanding, he added. He expressed gratitude and appreciation for the Saudi government's role in supporting development in Yemen.