KABUL: Two explosions shook the Afghan capital on Tuesday, leaving seven army officers wounded after a bomb attack on their bus, while a grenade blast in the diplomatic quarter caused no casualties but led to the arrest of a suspect, officials said.

Kabul has suffered a growing number of bombings by the Taliban and other jihadist militants as foreign combat troops withdraw from a 13-year-long war, leaving behind a smaller support mission.

Early on Tuesday, a remote-controlled bomb exploded on the city's outskirts as a bus carrying Afghan army personnel passed by, said Zahir Azimi, a spokesman for the Afghan defence ministry. Seven of the bus passengers were injured.

In an email to journalists, the Taliban insurgency claimed responsibility for that attack.

A later blast shook houses in the Wazir Akbar Khan area of the city, which is home to embassies, international media offices and aid groups, but there were no casualties, police said.

“Someone threw a hand grenade and he was apprehended,” said Sediq Sediqqi, a spokesman for the interior ministry.

The suspect was being interrogated but his motive and target were still unclear, he added.

A day earlier, a magnetic bomb killed two US troops in the capital.