SEOUL (AFP) - South Korea announced on Wednesday a set of measures, including tax relief and special loans, to help firms hit by North Korea's closure of the Kaesong joint industrial zone.

"This is not enough to ease the suffering of affected companies ... this is just a start," Unification Ministry spokesman Kim Hyung Seok told reporters, promising more measures would follow.

North Korea has blocked South Korean access to Kaesong since April 3, amid soaring military tensions on the Korean peninsula.

On April 9, it pulled out all the 53,000 North Koreans working at the 123 South Korean firms in Kaesong and shut down the complex, which was established in 2004 as a rare symbol of inter-Korean cooperation.

The aid package involves a number of state bodies including the finance ministry and the national tax agency and will include guarantees for new bank loans and work training for those who lost jobs.

The tax office will hold off on conducting audits, and try to give hard pressed companies refunds on value added to taxes they already paid.

"Difficulties among the companies are getting ever more intense as the suspension has continued for more than two weeks now," Mr Kim said.

There are currently 176 South Korean workers still in Kaesong, compared to the normal number of around 850.

The North's decision to suspend operations was unexpected. Neither of the Koreas has allowed previous crises to significantly affect the complex, a valued source of hard currency for the impoverished North and seen as a bellwether of stability on the Korean peninsula.