LJUBLJANA -- Slovenia have planned two warm-up matches against Ghana and Tunisia before they depart for Asia for the World cup.

They have been drawn in group B with Paraguay, South Africa and Spain in the first phase of the World Cup finals.

Slovenia coach Srecko Katanec was very pleased with his team's performance in Wednesday's World Cup warm-up match against Croatia in Zagreb, which finished goalless.

"We've played an extraordinary good match ... the Croats, who still are number three in the world, did not have a single good scoring opportunity," Katanec told a news conference.

"There is still enough time to work on the players' condition and the forwards," he added.

The coach admitted that some of his players, who are not regular first-choices in their respective clubs, still have a lot of work to do to get in shape for South Korea and Japan.

Katanec also criticised the new ball that will be used at the finals and said players from other country's were also still trying to get used to them.

"These balls are extremely bad, very hard to control and their elasticity is still hard to cope with." said the former international defender.

Slovenian football association president Rudi Zavrl said the match in Zagreb had been preceded by some unsavoury incidents, including the Slovenia team bus being hit by a stone which broke the wind-shield.

Croatia police said on Thursday that ten people -- six Croats and four Slovenes -- were detained during and after the match for attacking policemen.

Seven Slovenes and a U.S. citizens were given medical assistance and nine cars and a bus with Slovenian plates were damaged, the police added.