A spokesman for the international peacekeeping mission in Darfur says Sudanese authorities have arrested two people in connection with an ambush earlier this week on joint U.N.-African Union forces.

Noureddine Mezni said Thursday government troops captured the two suspects outside the south Darfur capital of Nyala a day earlier. Authorities also recovered one of two U.N.-AU vehicles stolen in the attack.

The arrests come after gunmen attacked a police convoy outside Nyala on Tuesday, wounding seven Pakistani police officers serving with the U.N.-AU force. Four of them are in critical condition. The 26,000-strong U.N. mission in Darfur has a mandate to help protect civilians, ensure the delivery of humanitarian aid, and bring peace and security to the territory.

UN Secretary General Ban Ki-moon condemned on Wednesday the attack by unidentified armed assailants that injured seven peacekeepers in Sudan's Darfur region.

The attack against a convoy of police of the UN-African Union Mission in Darfur (UNAMID) took place in Nyala, in south Darfur. The police were conducting a patrol in the El Sharif refugee camp on Tuesday when they were attacked. Ban called on the government of Sudan to immediately investigate the incident and bring the attackers before justice.