Pakistan and the US came to blows on Thursday after ground forces from the two countries exchanged fire over the border with Afghanistan. One of our Observers in Pakistan says the army was right to defend the country and is ready to fight, while another says the incident was no more than a "lovers' quarrel".

The two countries refuse to admit who's to blame for the crossfire, which follows weeks of escalating tension as US troops move further into Pakistan as part of the "war on terror". Pakistan's new president, Asif Ali Zardari, is largely perceived as an ally of America. But since he was instated last Saturday, he's had to face the challenge of military confrontation with the world's most formidable army. According to Zardari, Pakistani forces set off two flares to warn US helicopters that they had crossed into Pakistani airspace on Thursday. The US, on the other hand, denies that its aircraft had crossed the border, arguing that they returned real fire to warn the ground troops to stop shooting.

"The Americans put Zardari into power… for a reason"

Zaheer Kidvai is a lecturer in Karachi.

I'm worried - I don't want to see my house bombed and my wife or daughter killed, but I don't think it will come to that. This is a lovers' quarrel. It will continue - the Americans will keeping pushing and testing... we will fire a few rockets now and then. It will look good on paper. We can't got to war with America, and America won't go too far either. They need support from these places. The Americans put Zardari into power, and they did it for a reason. It was a negotiated deal. They wouldn't have done that if they wanted to launch a full scale war.

Now that Musharraf's party is not in power, there's a little less fundamentalism being promoted on the TV. The average uneducated person might therefore be pushed into making their own choice, and they might be drawn towards Islam more. This will certainly cause more terrorists! I don't know of any Pakistani who genuinely believes the US is doing a good thing by coming into Pakistan."

"I myself am ready to sacrifice my life"

Awab Alvi is a dentist from Karachi.

Of course it wasn't flares - they were shots and I'm proud to say it. The reason he [Zardari] said it was a flare was to soften the blow, but he shouldn't have - we have the right to defend our country.

Here in Pakistan we have homegrown terrorists, Taliban terrorists squeezed out of Afghanistan because of the "war on terror", and now we have a third kind of terrorist - the American army. We have enough terrorists! But the US won't listen. They don't communicate with the Pakistani army. I think it's going to get much worse. All the US wants to do is bomb bomb bomb until nothing remains. That's not going to work; it will only create more terrorists - terrorists that are not Islamic extremists. They're just fighting for their country. And if it gets much worse, then I myself am ready to sacrifice my life. I am a person who would commit and die for my country. And we don't want that. Let us handle this ourselves. We need peaceful solutions and negotiation."