At least four people were killed after an explosion occurred at a sports club in a key Sudanese Red Sea port city, according to officials Sunday.

The incident took place late Saturday at a busy sporting club in Port Sudan.

Witnesses said that unidentified gunmen on a motorcycle carried out an armed attack. However, it was not immediately clear who was behind the attack.

"An explosive device went off at Al-Amir club ... killing four people," the Central Committee of Sudan Doctors said in a statement.

Additionally, three others were wounded after being shot or stabbed, the statement added.

"There was another attempt targeting a hotel in the city but it failed," the committee said without giving further details.

Local authorities announced in a statement Sunday that one of the attackers had been arrested.