KARACHI: Pakistani police on Tuesday probed a string of blasts which killed one person and wounded 37 in Karachi, the second deadly attack in as many days to hit the frontline state in the US "war on terror".

The series of six explosions in the volatile southern port city came a day after a suicide bombing in the capital Islamabad killed 19 people near a rally marking the first anniversary of a bloody government raid on a radical mosque.

Pakistan's new government is facing growing unrest despite beating embattled President Pervez Musharraf's allies in elections in February, with Islamist violence on the rise and political divisions growing.

Five men were being questioned on Tuesday after they were arrested in connection with the blasts, said Babar Khattak, the police chief of Sindh province, of which Karachi is the capital.

"We have detained five people from different parts of the city after our investigators got some leads about their involvement in the blasts," Khattak told AFP.

"We cannot disclose to which group they belong or what we have recovered from them," he said.

Provincial chief minister Qaim Ali Shah said Monday evening's bombs were meant to "destabilise the coalition government" which won the national elections, state media said.

The government comprises the party of former premier Benazir Bhutto, who was assassinated in December, and the grouping of ex-prime minister Nawaz Sharif.

There was no claim of responsibility for the blasts but television channels quoted Shah as saying that authorities had been forewarned about Taliban militants from the northwestern border with Afghanistan.

Interior ministry chief Rehman Malik however said in a statement that the blasts were an "effort by anti-state and anti-social elements to create panic, fear and insecurity amongst the general public in Karachi."

Police said that the blasts were likely to be an attempt to stir up ethnic tensions in the troubled city because most happened in areas populated by Pashtuns, who originally hail from the northwestern frontier with Afghanistan.

Investigators were meanwhile trying to establish who was behind Sunday's blast in Islamabad, which hit police guarding a protest by Islamists against the deaths of more than 100 people in the siege and storming of the Red Mosque.

Last July's operation against the mosque unleashed a wave of revenge suicide attacks that left around 1,000 people dead.

UN chief Ban Ki-moon condemned the Islamabad blast in a statement overnight, calling on "all political forces to unite against the scourge of terrorism".

There was no immediate claim of responsibility but officials said they were examining a range of possible culprits, including the mosque's former students and Pakistani Taliban.

Pakistan's government is under growing pressure from the United States and other Western allies with troops in Afghanistan over negotiations that it launched with Taliban militants after coming to power.

Kabul has also piled pressure on Islamabad to tackle Taliban rebels based near the border, with a suicide car bomb attack on the Indian embassy in the Afghan capital on Monday leaving 41 dead and around 150 injured.

The Afghan interior ministry said "terrorists" had carried out the Kabul attack "in coordination and with advice from regional intelligence circles" but declined to comment when asked if this was a reference to Pakistan.

Afghanistan has repeatedly accused Pakistan's intelligence agencies of supporting the Taliban. Islamabad backed the hard-line regime during its 1996-2001 rule but denies any current links to the militia.

- AFP/yb